{"id":8865,"date":"2015-04-16T17:11:37","date_gmt":"2015-04-16T22:11:37","guid":{"rendered":"https:\/\/www.masterorganicchemistry.com\/?p=8865"},"modified":"2026-04-18T06:31:37","modified_gmt":"2026-04-18T11:31:37","slug":"elimination-reactions-of-alcohols","status":"publish","type":"post","link":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/","title":{"rendered":"Elimination Reactions of Alcohols"},"content":{"rendered":"<p><strong>All About Elimination Reactions of Alcohols (With Acid)<\/strong><\/p>\n<ul>\n<li>The hydroxyl group of alcohols is normally a poor leaving group.<\/li>\n<li>However, when treated with strong acid, R-OH is converted into R-OH<sub>2<\/sub>(+) and H<sub>2<\/sub>O is a much better leaving group.<\/li>\n<li>With tertiary alcohols, H<sub>2<\/sub>O can then leave, resulting in a carbocation.<\/li>\n<li>If a strong acid such as H<sub>2<\/sub>SO<sub>4<\/sub> or p-TsOH is used, the most likely result is <strong>elimination<\/strong>, since the conjugate bases of these acids (HSO<sub>4<\/sub> <sup>&#8211;<\/sup> and TsO<sup>&#8211;<\/sup> ) are poor nucleophiles and unlikely to add to the carbocation.<\/li>\n<\/ul>\n<p><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone wp-image-36160\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2015\/04\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif\" alt=\"summary of elimination reactions of alcohol with strong acid such as H2SO4 and heat E1 mechanism\" width=\"640\" height=\"536\" \/><\/a><\/p>\n<p><strong>Table of Contents<\/strong><\/p>\n<ol>\n<li><a href=\"#one\">Hydrohalic Acids (HX) Plus Alcohols Give Substitution Products&#8230;<\/a><\/li>\n<li><a href=\"#two\">&#8230;But H<sub>2<\/sub>SO<sub>4<\/sub>, H3PO4, and TsOH Give Elimination Products!<\/a><\/li>\n<li><a href=\"#three\">Elimination of Tertiary Alcohols Proceeds Through an E1 Mechanism<\/a><\/li>\n<li><a href=\"#four\">Why Do H2SO4, H3PO4 and TsOH Give Elimination Products?\u00a0<\/a><\/li>\n<li><a href=\"#five\">What About Secondary Alcohols?<\/a><\/li>\n<li><a href=\"#six\">Elimination Reactions With Carbocation Rearrangements<\/a><\/li>\n<li><a href=\"#seven\">Ring Expansion Followed By Elimination<\/a><\/li>\n<li><a href=\"#eight\">Primary Alcohols and H2SO4 Can Form Alkenes (via E2)<\/a><\/li>\n<li><a href=\"#nine\">Summary: Elimination Reactions of Alcohols<\/a><\/li>\n<li><a href=\"#notes\">Notes<\/a><\/li>\n<li><a href=\"#quizzes\">Quiz Yourself!\u00a0<\/a><\/li>\n<li><a href=\"#references\">(Advanced) References and Further Reading<\/a><\/li>\n<\/ol>\n<hr \/>\n<h2><a id=\"one\"><\/a>1. Hydrohalic acids (HX) \u00a0plus alcohols give substitution products&#8230;<\/h2>\n<p>Previously (<em>See post: <a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/02\/27\/making-alkyl-halides-from-alcohols\/\">Making Alkyl Halides from Alcohols<\/a><\/em>) we saw that treating an alcohol with a strong hydrohalic acid &#8211; think HCl, HBr, or HI &#8211; resulted in the formation of alkyl halides. With a tertiary alcohol like the one drawn below, this proceeds through an S<sub>N<\/sub>1 mechanism. <span style=\"color: #993366;\"><em>[Protonation of alcohol, then loss of H<sub>2<\/sub>O to form a carbocation, then attack of nucleophile on carbocation].<\/em><\/span><\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-15211\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/1-recall-that-alcohols-plus-hydrohalic-acids-give-alkyl-halides-through-sn1-or-sn2-depending-on-substrate.gif\" alt=\"recall that alcohols plus hydrohalic acids give alkyl halides through sn1 or sn2 depending on substrate\" width=\"630\" height=\"214\" \/><\/p>\n<h2><a id=\"two\"><\/a>2. &#8230;But H<sub>2<\/sub>SO<sub>4<\/sub>, H<sub>3<\/sub>PO<sub>4<\/sub>, and TsOH Give Elimination Products!<\/h2>\n<p>You&#8217;d be forgiven for\u00a0thinking that if we treated an alcohol with H<sub>2<\/sub>SO<sub>4<\/sub> (sulfuric acid) the same type of thing would occur, and the carbocation would be attacked by the (-)OSO<sub>3<\/sub>H anion to make the product below. Very reasonable to propose. In practice, however, it doesn&#8217;t work that way!<\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-15212\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/2-use-of-tertiary-alcohols-with-h2so4-h3po4-and-tsoh-give-elimination-products-via-e1-carbocation-formation.gif\" alt=\"use of tertiary alcohols with h2so4 h3po4 and tsoh give elimination products via e1 carbocation formation\" width=\"630\" height=\"366\" \/><\/p>\n<p>So what happened here?<\/p>\n<p>First, look at <strong>what<\/strong> bonds formed and broke. We formed C-C (\u03c0) and broke C-OH and C-H. <span style=\"color: #993366;\"><em>(We also formed H-O , in that molecule of water that forms\u00a0as a byproduct)<\/em><\/span>. This is the pattern of an <a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/10\/10\/introduction-to-elimination-reactions\/\"><strong>elimination<\/strong><\/a> reaction.<\/p>\n<p>Now let&#8217;s ask: <strong>How<\/strong> could this have formed? If you look closely, note that we&#8217;ve broken a C-H bond on the carbon adjacent to the carbocation and formed a new C-C \u03c0 bond at that spot. It&#8217;s reasonable to propose that instead of attacking the carbocation to form a new substitution product, a \u00a0<strong>base removed a proton adjacent to the carbocation and formed the alkene<\/strong>. <span style=\"color: #993366;\"><em>[That carbon adjacent to the carbocation is often referred to as the &#8220;\u03b2 (beta) carbon&#8221;. The carbocation itself is the &#8220;\u03b1 (alpha) carbon&#8221;].<\/em><\/span><\/p>\n<h2><a id=\"three\"><\/a>3. Elimination of Tertiary Alcohols Proceeds Through an E1 Mechanism<\/h2>\n<p>We&#8217;ve seen this type of process before actually!\u00a0<a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/09\/19\/the-e1-reaction\/\">This is an E1 process<\/a>\u00a0<span style=\"color: #993366;\"><em>[elimination (E) , unimolecular (1) rate determining step]<\/em><\/span>. You might also remember that elimination reactions tend to follow &#8220;<a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/08\/31\/elimination-reactions-2-zaitsevs-rule\/\">Zaitsev&#8217;s rule<\/a>&#8221; &#8211; we always form the most substituted alkene<span style=\"color: #993366;\"><em> [or to put it another way, we remove a proton from the carbon with the\u00a0fewest attached hydrogens]<\/em><\/span> because alkene stability increases as we increase the number of attached carbons.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15213\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/3-mechanism-for-elimination-of-tertiary-alcohols-using-h2so4-protonation-of-alcohol-step-2-loss-of-leaving-group-step-3-deprotonation-giving-alkene-zaitsev.gif\" alt=\"mechanism for elimination of tertiary alcohols using h2so4 protonation of alcohol step 2 loss of leaving group step 3 deprotonation giving alkene zaitsev\" width=\"630\" height=\"230\" \/><\/p>\n<p><span style=\"color: #993366;\"><em>[By the way, you might ask &#8211; why &#8220;heat&#8221; ? <a style=\"color: #993366;\" href=\"https:\/\/www.masterorganicchemistry.com\/2012\/09\/10\/elimination-reactions-are-favored-by-heat\/\">Heat generally tends to favour elimination reactions.<\/a>]<\/em><\/span><\/p>\n<p>By no means is H<sub>2<\/sub>SO<sub>4<\/sub> the only acid that does this. Phosphoric acid (H<sub>3<\/sub>PO<sub>4<\/sub>) as well as &#8220;tosic acid&#8221; (p-toluenesulfonic acid) also tend to form elimination products.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15214\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/4-other-choice-for-e1-elimination-of-alcohols-use-phosphoric-acid-h3po4-or-tosic-acid-tsoh.gif\" alt=\"other choice for e1 elimination of alcohols use phosphoric acid h3po4 or tosic acid tsoh\" width=\"600\" height=\"247\" \/><\/p>\n<h2><a id=\"four\"><\/a>4. Why Does H<sub>2<\/sub>SO<sub>4<\/sub> (Or H<sub>3<\/sub>PO<sub>4<\/sub> or TsOH) Give Elimination Products But HCl, HBr, HI give Substitution Products?<\/h2>\n<p>So why do we get elimination reactions with H<sub>2<\/sub>SO<sub>4<\/sub> as acid (or H<sub>3<\/sub>PO<sub>4<\/sub>, or TsOH) whereas we get substitution reactions with HCl, HBr, and HI?<\/p>\n<p>The answer is that<strong> the\u00a0HSO<sub>4<\/sub>&#8211; \u00a0anion is a very poor nucleophile<\/strong>\u00a0, being quite stabilized by resonance. In the diagram below, note how that negative charge is delocalized over three different oxygens <span style=\"color: #993366;\"><em>[the same is true for the TsO<sup>\u2013 <\/sup>and H<sub>2<\/sub>PO<sub>4<\/sub><sup>\u2013<\/sup> anions].\u00a0\u00a0<\/em><\/span><\/p>\n<p>Compare that to halide anions, where the negative charge cannot be spread over more than one atom. The upshot is that delocalization of charge results in a slower reaction of HSO<sub>4<\/sub>&#8211; as a nucleophile compared to deprotonation of C-H by a base, and the alkene product dominates.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15215\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/5-tsoh-and-hso4-are-resonance-stabilized-anions-and-poor-nucleophiles.gif\" alt=\"tsoh and hso4 are resonance stabilized anions and poor nucleophiles\" width=\"630\" height=\"241\" \/><\/p>\n<p>So the bottom line here is that heating tertiary alcohols with these acids will result in loss of water [&#8220;dehydration&#8221;] and formation of an alkene [elimination].<\/p>\n<h2><a id=\"five\"><\/a>5. What About Elimination Reactions Of Secondary Alcohols?<\/h2>\n<p>Heating a secondary alcohol with sulfuric acid or phosphoric acid? Same deal as with tertiary alcohols: expect an alkene to form. As with all elimination reactions, there are two things to watch out for: first, the &#8220;most substituted&#8221; alkene (Zaitsev) will be the dominant product, and also, don&#8217;t forget that <em>trans<\/em> alkenes will be favoured (more stable) than <em>cis<\/em> alkenes due to less steric strain.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15216\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/6-secondary-alcohols-and-phosphoric-acid-leads-to-elimination-reaction-as-with-h2so4-gives-zaitsev-product-favors-trans-alkene.gif\" alt=\"secondary alcohols and phosphoric acid leads to elimination reaction as with h2so4 gives zaitsev product favors trans alkene\" width=\"600\" height=\"217\" \/><\/p>\n<p>There is one last thing to watch out for with secondary alcohols, though&#8230; like a bad nightmare, they keep coming back.<\/p>\n<h2><a id=\"six\"><\/a>6. Elimination\u00a0 Reactions With Carbocation Rearrangements<\/h2>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/02\/27\/making-alkyl-halides-from-alcohols\/\">As we saw with the reactions of HCl, HBr, and HI with secondary alcohols<\/a>, we have to watch out for <strong>carbocation rearrangement reactions<\/strong>. If a more stable carbocation can be formed through migration of an adjacent hydride (H- ) \u00a0or an alkyl group, then that migration will occur.<\/p>\n<p>For example, treatment of the alcohol below with H<sub>2<\/sub>SO<sub>4<\/sub> leads to formation of a secondary carbocation, followed by a hydride shift to give a tertiary carbocation, followed by deprotonation at whichever \u03b2\u00a0carbon leads to the most substituted alkene.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15217\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/7-alcohol-elimination-reaction-with-strong-acid-with-hydride-shift-step-by-step-mechanism-protonation-loss-of-leaving-group-hydride-shift-deprotonation.gif\" alt=\"alcohol elimination reaction with strong acid with hydride shift step by step mechanism protonation loss of leaving group hydride shift deprotonation\" width=\"630\" height=\"426\" \/><\/p>\n<h2><a id=\"seven\"><\/a>7. Ring Expansion Followed By Elimination<\/h2>\n<p>It&#8217;s also possible for\u00a0<strong>alkyl<\/strong> shifts to occur to give a more stable carbocation. A classic example of this are expansions of strained rings (like cyclobutanes) to give less strained rings (like cyclopentanes).<\/p>\n<p>For example in the case below the key step is where the C3-C4 bond breaks to form the C2-C4 bond, resulting in a new (tertiary) carbocation on C-3 as well as a less strained ring. Since there isn&#8217;t a good nucleophile around, elimination occurs in such a way that the <strong>most substituted<\/strong> alkene is formed.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15218\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/8-elimination-of-alcohol-with-ring-expansion-using-h2so4-example-protonation-loss-of-leaving-group-alkyl-shift-deprotonation-rearrangement-mechanism.gif\" alt=\"elimination of alcohol with ring expansion using h2so4 example protonation loss of leaving group alkyl shift deprotonation rearrangement mechanism\" width=\"600\" height=\"393\" \/><\/p>\n<h2><a id=\"eight\"><\/a>8. Primary\u00a0 Alcohols And H<sub>2<\/sub>SO<sub>4<\/sub> Can Form Alkenes (E2)<\/h2>\n<p>The final class of alcohols to be concerned about is primary alcohols. You might ask: if we treat a primary alcohol (say, 1-butanol) with a strong acid like H<sub>2<\/sub>SO<sub>4<\/sub>, will also get elimination to an alkene?<\/p>\n<p>Yes, alkenes can be formed this way (along with some formation of symmetrical ethers\u00a0<em>[<a href=\"https:\/\/www.masterorganicchemistry.com\/2014\/11\/14\/ether-synthesis-via-alcohols-and-acid\/\">see this previous post<\/a>]).<\/em> Here&#8217;s an example.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15219\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/9-primary-alcohols-dehydration-to-alkenes-with-h2so4-probably-through-e2-reaction.gif\" alt=\"primary alcohols dehydration to alkenes with h2so4 probably through e2 reaction\" width=\"600\" height=\"168\" \/><\/p>\n<p>There is a catch however: \u00a0the E1 pathway (formation of a primary carbocation) is not the most likely pathway here. <strong>Primary carbocations tend to be extremely unstable<\/strong>, and it&#8217;s more likely that the reaction passes through an E2 mechanism where the transition state will be lower in energy. Notice what happens here: first we protonate the alcohol to give the good leaving group OH<sub>2<\/sub>+ , and then a weak base (which I&#8217;m leaving vague, but could be H<sub>2<\/sub>O, (-)OSO<sub>3<\/sub>H, or another molecule of the alcohol) could then break C-H, leading to formation of the alkene.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15220\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/10-mechanism-for-formation-of-alkenes-from-protonation-of-primary-alcohols-with-h2so4-and-heat-likely-goes-through-e2-with-weak-base.gif\" alt=\"mechanism for formation of alkenes from protonation of primary alcohols with h2so4 and heat likely goes through e2 with weak base\" width=\"600\" height=\"314\" \/><\/p>\n<h2><a id=\"nine\"><\/a>9. Summary: Elimination Reactions of Alcohols (E1)<\/h2>\n<p>If you see a tertiary or secondary alcohol with H<sub>2<\/sub>SO<sub>4<\/sub>, TsOH, or H<sub>3<\/sub>PO<sub>4<\/sub> (and <strong>especially<\/strong> if you see &#8220;heat&#8221;)\u00a0think: carbocation formation followed by elimination reaction (E1).<\/p>\n<p>And if you see that a more stable carbocation could be formed through migration of an adjacent H or alkyl group, expect that to happen.<\/p>\n<p>If you see a <strong>primary<\/strong> alcohol with H<sub>2<\/sub>SO<sub>4<\/sub>, TsOH, or H<sub>3<\/sub>PO<sub>4<\/sub>, expect symmetrical ether formation accompanied by elimination to form the alkene.<\/p>\n<h3>Next Time&#8230;<\/h3>\n<p>So far we&#8217;ve learned two ways to convert alcohols to alkenes:<\/p>\n<ul>\n<li>convert them to a good leaving group, and then add base (2 steps)<\/li>\n<li>add strong acid with heat (one step)<\/li>\n<\/ul>\n<p>Ideally, we&#8217;d like to just use one step. But strong acid can lead to complications (carbocation rearrangements, cough cough) and we might ask: &#8220;isn&#8217;t there an easier way&#8221;?<br \/>\nThere is! That&#8217;s what we&#8217;ll cover in the next post.<\/p>\n<p><strong>Next Post: <a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/04\/28\/elimination-of-alcohols-to-alkenes-with-pocl3\/\">Elimination Of Alcohols To Alkenes With POCl<sub>3<\/sub><\/a><\/strong><\/p>\n<hr \/>\n<h2><a id=\"notes\"><\/a>Notes<\/h2>\n<div class=\"related-articles\"><p><strong>Related Articles<\/strong><\/p><ul><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/04\/28\/elimination-of-alcohols-to-alkenes-with-pocl3\/\" class=\"\"><span>Elimination of Alcohols To Alkenes With POCl3<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/09\/19\/the-e1-reaction\/\" class=\"\"><span>The E1 Reaction<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/02\/27\/making-alkyl-halides-from-alcohols\/\" class=\"\"><span>Making Alkyl Halides From Alcohols<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/03\/10\/tosylates-and-mesylates\/\" class=\"\"><span>Tosylates And Mesylates<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/09\/10\/elimination-reactions-are-favored-by-heat\/\" class=\"\"><span>Elimination Reactions Are Favored By Heat<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/08\/31\/elimination-reactions-2-zaitsevs-rule\/\" class=\"\"><span>Elimination Reactions (2): The Zaitsev Rule<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/11\/09\/e1-reaction-rearrangement\/\" class=\"\"><span>Elimination (E1) Reactions With Rearrangements<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2016\/09\/27\/uv-vis-spectroscopy-some-practice-questions\/\" class=\"\"><span>Elimination (E1) Practice Problems And Solutions (MOC Membership)<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/03\/11\/3-factors-that-stabilize-carbocations\/\" class=\"\"><span>3 Factors That Stabilize Carbocations<\/span><\/a><\/li><\/ul><\/div>\n<hr \/>\n<h2><a id=\"quizzes\"><\/a>Quiz Yourself!<\/h2>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3601-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0247-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3648-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0245-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <br \/>\n<\/p>\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0230-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <br \/>\n<\/p>\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0231-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <br \/>\n<\/p>\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0239-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3645-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n<hr \/>\n<h2><a id=\"references\"><\/a>(Advanced) References and Further Reading<\/h2>\n<p>A variety of conditions are possible for this transformation (alcohol -&gt; alkene), all of which involve converting the -OH into a better leaving group. The use of acid is the simplest method to achieve this, as protonation of -OH gives -OH<sub>2<\/sub><sup>+<\/sup>, an excellent leaving group (water).<\/p>\n<p>Elimination with POCl<sub>3<\/sub>:<\/p>\n<ol>\n<li><strong>The Effect of Structure on the Course of Phosphoryl Chloride-Pyridine Dehydration of Tertiary Alcohols<br \/>\n<\/strong>Ronald R. Sauers<strong><br \/>\n<\/strong><em>Journal of the American Chemical Society<\/em><strong> 1959 <\/strong><em>81<\/em> (18), 4873-4876<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/10.1021\/ja01527a028\">1021\/ja01527a028<\/a><\/li>\n<li><strong>Stereospecificity and regiospecificity of the phosphorus oxychloride dehydration of sterol side chain alcohols<br \/>\n<\/strong>Jose Luis Giner, Christian Margot, and Carl Djerassi<br \/>\nThe Journal of Organic Chemistry <strong>1989<\/strong> <em>54<\/em> (2), 369-373<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/jo00263a020\">1021\/jo00263a020<\/a><br \/>\nThis article by the legendary chemist Carl Djerassi (who developed norethindrone, the first female contraceptive) describes the selectivity of POCl<sub>3<\/sub>-pyridine dehydration conditions in steroid synthesis. It also has a general procedure for POCl<sub>3<\/sub>-pyridine dehydration in the experimental section.<\/li>\n<li><strong>A general approach to linearly fused triquinane natural products. Total syntheses of (.+-.)-hirsutene, (.+-.)-coriolin, and (.+-.)-capnellene<br \/>\n<\/strong>Goverdhan Mehta, A. Narayana. Murthy, D. Sivakumar. Reddy, and A. Veera. Reddy<strong><br \/>\n<\/strong><em>Journal of the American Chemical Society<\/em> <strong>1986<\/strong> <em>108<\/em> (12), 3443-3452<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/abs\/10.1021\/ja00272a046\">1021\/ja00272a046<\/a><br \/>\nThis paper by Prof. Goverdhan Mehta (considered the \u2018Indian E. J. Corey\u2019) demonstrates the applicability of the POCl<sub>3<\/sub>-pyridine dehydration in natural product total synthesis.<\/li>\n<li><strong> The 3-methylcholestanols and their derivatives<br \/>\n<\/strong>D. H. R. Barton, A. da S. Campos-Neves and R. C. Cookson<br \/>\n<em>J. Chem. Soc., <\/em><strong>1956<\/strong><em>, <\/em>3500-3506<br \/>\n<strong>DOI:<\/strong> <a href=\"https:\/\/pubs.rsc.org\/en\/Content\/ArticleLanding\/JR\/1956\/JR9560003500#!divAbstract\">10.1039\/JR9560003500<\/a><br \/>\nThis paper by Nobel Laureate Prof. Derek H. R. Barton has a POCl3-pyridine dehydration (see p. 3504-3505 in the experimental section).Using a Br\u00f8nsted acid:<\/li>\n<li><strong>THE COMPOSITION OF BUTENE MIXTURES RESULTING FROM THE CATALYTIC DECOMPOSITION OF THE NORMAL BUTYL ALCOHOLS<br \/>\n<\/strong>William G. Young and Howard J. Lucas<strong><br \/>\n<\/strong><em>Journal of the American Chemical Society<\/em><strong> 1930, <\/strong><em>52<\/em> (5), 1964-1970<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/abs\/10.1021\/ja01368a030\">1021\/ja01368a030<\/a><br \/>\nWhile this would seem to be an easy thing to study today, with NMR and GC-MS, in the early days this was not so easy. The butenes were converted to dibromides, distilled, and then the three-component dibromide mixture analyzed by density, refractive index, and determination of the second-order rate constants with potassium iodide in acetone. Both Bill Young and H. J. Lucas contributed greatly to the development of chemistry in Southern California \u2013 H. J. Lucas was a professor of chemistry at Caltech, and Bill Young later became a professor of chemistry at UCLA, and was the advisor for Prof. Saul Winstein\u2019s M.S. in chemistry (Prof. Winstein ended up joining Bill Young at UCLA after his PhD!).<\/li>\n<li><strong>The Dehydration of Secondary and Tertiary Alcohols<br \/>\n<\/strong>Albert L. Henne and Alfred H. Matuszak<strong><br \/>\n<\/strong><em>Journal of the American Chemical Society<\/em><strong> 1944, <\/strong><em>66<\/em> (10), 1649-1652<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/abs\/10.1021\/ja01238a012\">1021\/ja01238a012<\/a><strong><br \/>\n<\/strong>An early paper that demonstrates the E1 nature of this reaction, by demonstrating that dehydration of various secondary and tertiary alcohols give products obtained through rearrangement.<\/li>\n<li><strong> Tracer studies on alcohols. Part II. The exchange of oxygen-18 between sec.-butyl alcohol and water<br \/>\n<\/strong>C. A. Bunton and D. R. Llewellyn<strong><br \/>\n<\/strong><em>J. Chem. Soc.,<\/em><strong> 1957, <\/strong>3402-3407<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.rsc.org\/en\/content\/articlelanding\/1957\/JR\/jr9570003402#!divAbstract\">10.1039\/JR9570003402<\/a><strong><br \/>\n<\/strong>This paper provides experimental evidence that stronger acids favor elimination over substitution. As the Hammett acidity (-<em>H<sub>0<\/sub><\/em>) of the medium increases, carbocation formation is increasingly favorable, which promotes elimination over substitution. Sulfuric acid and perchloric acid are much stronger acids than the hydrogen acids (HCl, HBr, HI), which explains why sulfuric acid is commonly used to make olefins from alcohols.<\/li>\n<li><strong> Reactions of n-butene and butan-2-ol in dilute acid. The elucidation of the mechanism and the intermediate in elimination from secondary alcohols and in the hydration of olefins<br \/>\n<\/strong>Joost Manassen and Fritz S. Klein<strong><br \/>\n<\/strong><em>J. Chem. Soc.,<\/em><strong> 1960<\/strong>, 4203-4213<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.rsc.org\/en\/content\/articlelanding\/1960\/JR\/JR9600004203#!divAbstract\">10.1039\/JR9600004203<\/a><br \/>\nThe authors use radiolabeling to study both the forward and reverse reactions (hydration of alkene and elimination of alcohol), to prove that they both go through a common carbocation intermediate.<\/li>\n<li><strong>The mechanism of the acid-catalyzed dehydration of 1,2-diphenylethanol<br \/>\n<\/strong>Donald S. Noyce, Donald R. Hartter, and Ralph M. Pollack<strong><br \/>\n<\/strong><em>Journal of the American Chemical Society<\/em><strong> 1968, <\/strong><em>90<\/em> (14), 3791-3794<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/abs\/10.1021\/ja01016a034\">1021\/ja01016a034<\/a><br \/>\nInterestingly, in the reaction of 1,2-diphenylethanol in acid, formation of the intermediate carbocation is fast and reversible, and proton loss to the olefin is rate-determining.<\/li>\n<li><strong>The effect of substituents on the rate of the acid-catalyzed dehydration of 1,2-diarylethanols<br \/>\n<\/strong>Donald S. Noyce, Donald R. Hartter, and Frank B. Miles<strong><br \/>\n<\/strong><em>Journal of the American Chemical Society<\/em><strong> 1968, <\/strong><em>90<\/em> (14), 3794-3796<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/abs\/10.1021\/ja01016a035\">1021\/ja01016a035<\/a><br \/>\nIn this reaction, the effect of substitution on the phenyl ring a to the -OH is greater than that of substitution on the other ring.<\/li>\n<li><strong>Catalytic, Tunable, One-Step Bismuth(III) Triflate Reaction with Alcohols: Dehydration Versus Dimerization<br \/>\n<\/strong>Laura E. Kolsi, Jari Yli-Kauhaluoma, and V\u00e2nia M. Moreira<strong><br \/>\n<\/strong><em>ACS Omega<\/em><strong> 2018, <\/strong><em>3<\/em> (8), 8836-8842<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/10.1021\/acsomega.8b01401\">1021\/acsomega.8b01401<\/a><br \/>\nA modern variant of this reaction using Lewis Acids. The authors also show that these conditions can be used for forming dimers vs. simple elimination products. The dimer is formed by the carbocation reacting with the alkene.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>All About Elimination Reactions of Alcohols (With Acid) The hydroxyl group of alcohols is normally a poor leaving group. However, when treated with strong acid, <\/p>\n","protected":false},"author":1,"featured_media":36160,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1420],"tags":[167,169,860,1034,472,201,1059,1060,293,1061],"post_folder":[],"class_list":["post-8865","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-alcohols-epoxides-ethers","tag-alcohols","tag-alkenes","tag-carbocation","tag-dehydration","tag-e1","tag-elimination","tag-h2so4","tag-h3po4","tag-rearrangements","tag-tsoh"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Elimination Reactions of Alcohols &#8211; Master Organic Chemistry<\/title>\n<meta name=\"description\" content=\"All about elimination of alcohols using strong acids with non-nucleophilic counterions, such as H2SO4, H3PO4, and TsOH. Mostly E1, but E2 for primary cases.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Elimination Reactions of Alcohols &#8211; Master Organic Chemistry\" \/>\n<meta property=\"og:description\" content=\"All about elimination of alcohols using strong acids with non-nucleophilic counterions, such as H2SO4, H3PO4, and TsOH. Mostly E1, but E2 for primary cases.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/\" \/>\n<meta property=\"og:site_name\" content=\"Master Organic Chemistry\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/\" \/>\n<meta property=\"article:published_time\" content=\"2015-04-16T22:11:37+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-04-18T11:31:37+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2015\/04\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif\" \/>\n\t<meta property=\"og:image:width\" content=\"886\" \/>\n\t<meta property=\"og:image:height\" content=\"742\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/gif\" \/>\n<meta name=\"author\" content=\"James Ashenhurst\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"James Ashenhurst\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"15 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/\"},\"author\":{\"name\":\"James Ashenhurst\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/person\\\/78d83ec7d02b4b7365bade2cedaef80c\"},\"headline\":\"Elimination Reactions of Alcohols\",\"datePublished\":\"2015-04-16T22:11:37+00:00\",\"dateModified\":\"2026-04-18T11:31:37+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/\"},\"wordCount\":2361,\"commentCount\":46,\"publisher\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2015\\\/04\\\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif\",\"keywords\":[\"alcohols\",\"alkenes\",\"carbocation\",\"dehydration\",\"e1\",\"elimination\",\"h2so4\",\"h3po4\",\"rearrangements\",\"tsoh\"],\"articleSection\":[\"Alcohols, Epoxides and Ethers\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/\",\"name\":\"Elimination Reactions of Alcohols &#8211; Master Organic Chemistry\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2015\\\/04\\\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif\",\"datePublished\":\"2015-04-16T22:11:37+00:00\",\"dateModified\":\"2026-04-18T11:31:37+00:00\",\"description\":\"All about elimination of alcohols using strong acids with non-nucleophilic counterions, such as H2SO4, H3PO4, and TsOH. Mostly E1, but E2 for primary cases.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/#primaryimage\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2015\\\/04\\\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif\",\"contentUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2015\\\/04\\\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif\",\"width\":886,\"height\":742,\"caption\":\"summary of elimination reactions of alcohol with strong acid such as H2SO4 and heat E1 mechanism\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/04\\\/16\\\/elimination-reactions-of-alcohols\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Elimination Reactions of Alcohols\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#website\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\",\"name\":\"Master Organic Chemistry\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\",\"name\":\"Master Organic Chemistry\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/04\\\/cutmypic.png\",\"contentUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/04\\\/cutmypic.png\",\"width\":225,\"height\":225,\"caption\":\"Master Organic Chemistry\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/Master-Organic-Chemistry-242610599108055\\\/\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/person\\\/78d83ec7d02b4b7365bade2cedaef80c\",\"name\":\"James Ashenhurst\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"caption\":\"James Ashenhurst\"},\"description\":\"Ph.D. 2006, McGill University (James L. Gleason). Postdoctoral Associate, 2008-2010, Massachusetts Institute of Technology (M. Movassaghi). Founder, Master Organic Chemistry, 2010-present.\",\"sameAs\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/about\\\/\"],\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/author\\\/james\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Elimination Reactions of Alcohols &#8211; Master Organic Chemistry","description":"All about elimination of alcohols using strong acids with non-nucleophilic counterions, such as H2SO4, H3PO4, and TsOH. Mostly E1, but E2 for primary cases.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/","og_locale":"en_US","og_type":"article","og_title":"Elimination Reactions of Alcohols &#8211; Master Organic Chemistry","og_description":"All about elimination of alcohols using strong acids with non-nucleophilic counterions, such as H2SO4, H3PO4, and TsOH. Mostly E1, but E2 for primary cases.","og_url":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/","og_site_name":"Master Organic Chemistry","article_publisher":"https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/","article_published_time":"2015-04-16T22:11:37+00:00","article_modified_time":"2026-04-18T11:31:37+00:00","og_image":[{"width":886,"height":742,"url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2015\/04\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif","type":"image\/gif"}],"author":"James Ashenhurst","twitter_card":"summary_large_image","twitter_misc":{"Written by":"James Ashenhurst","Est. reading time":"15 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/#article","isPartOf":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/"},"author":{"name":"James Ashenhurst","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/person\/78d83ec7d02b4b7365bade2cedaef80c"},"headline":"Elimination Reactions of Alcohols","datePublished":"2015-04-16T22:11:37+00:00","dateModified":"2026-04-18T11:31:37+00:00","mainEntityOfPage":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/"},"wordCount":2361,"commentCount":46,"publisher":{"@id":"https:\/\/www.masterorganicchemistry.com\/#organization"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/#primaryimage"},"thumbnailUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2015\/04\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif","keywords":["alcohols","alkenes","carbocation","dehydration","e1","elimination","h2so4","h3po4","rearrangements","tsoh"],"articleSection":["Alcohols, Epoxides and Ethers"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/","url":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/","name":"Elimination Reactions of Alcohols &#8211; Master Organic Chemistry","isPartOf":{"@id":"https:\/\/www.masterorganicchemistry.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/#primaryimage"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/#primaryimage"},"thumbnailUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2015\/04\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif","datePublished":"2015-04-16T22:11:37+00:00","dateModified":"2026-04-18T11:31:37+00:00","description":"All about elimination of alcohols using strong acids with non-nucleophilic counterions, such as H2SO4, H3PO4, and TsOH. Mostly E1, but E2 for primary cases.","breadcrumb":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/#primaryimage","url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2015\/04\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif","contentUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2015\/04\/0-summary-of-elimination-reactions-of-alcohol-with-strong-acid-such-as-H2SO4-and-heat-E1-mechanism.gif","width":886,"height":742,"caption":"summary of elimination reactions of alcohol with strong acid such as H2SO4 and heat E1 mechanism"},{"@type":"BreadcrumbList","@id":"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.masterorganicchemistry.com\/"},{"@type":"ListItem","position":2,"name":"Elimination Reactions of Alcohols"}]},{"@type":"WebSite","@id":"https:\/\/www.masterorganicchemistry.com\/#website","url":"https:\/\/www.masterorganicchemistry.com\/","name":"Master Organic Chemistry","description":"","publisher":{"@id":"https:\/\/www.masterorganicchemistry.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.masterorganicchemistry.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.masterorganicchemistry.com\/#organization","name":"Master Organic Chemistry","url":"https:\/\/www.masterorganicchemistry.com\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/logo\/image\/","url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/04\/cutmypic.png","contentUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/04\/cutmypic.png","width":225,"height":225,"caption":"Master Organic Chemistry"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/"]},{"@type":"Person","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/person\/78d83ec7d02b4b7365bade2cedaef80c","name":"James Ashenhurst","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","caption":"James Ashenhurst"},"description":"Ph.D. 2006, McGill University (James L. Gleason). Postdoctoral Associate, 2008-2010, Massachusetts Institute of Technology (M. Movassaghi). Founder, Master Organic Chemistry, 2010-present.","sameAs":["https:\/\/www.masterorganicchemistry.com\/about\/"],"url":"https:\/\/www.masterorganicchemistry.com\/author\/james\/"}]}},"_links":{"self":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts\/8865","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/comments?post=8865"}],"version-history":[{"count":0,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts\/8865\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/media\/36160"}],"wp:attachment":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/media?parent=8865"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/categories?post=8865"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/tags?post=8865"},{"taxonomy":"post_folder","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/post_folder?post=8865"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}