{"id":2726,"date":"2011-11-10T12:00:52","date_gmt":"2011-11-10T12:00:52","guid":{"rendered":"https:\/\/www.masterorganicchemistry.com\/?p=2726"},"modified":"2026-01-20T12:37:17","modified_gmt":"2026-01-20T18:37:17","slug":"dont-be-futyl-learn-the-butyls","status":"publish","type":"post","link":"https:\/\/www.masterorganicchemistry.com\/2011\/11\/10\/dont-be-futyl-learn-the-butyls\/","title":{"rendered":"Don’t Be Futyl, Learn The Butyls"},"content":{"rendered":"

There are four<\/strong> different types of “butyls”, and they all have their own name.<\/p>\n

In addition they each have a common name (“trivial name”) which they commonly go by. \u00a0It’s easy to get confused. So today’s post is a guide to sorting them out.<\/p>\n

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Butane has four carbons. Now there’s two potential ways to organize those carbons – the 4-carbon straight chain (n<\/em>-butane), and the 3-carbon chain with a methyl group on carbon #2 (2-methyl propane, also known as “isobutane”). \u00a0Don’t believe me? Try it out for yourself. There’s only two ways to do it.<\/p>\n

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Now let’s say we have some substituent. For example, let’s make it OH. Let’s remove a hydrogen from butane and replace it with OH. If you look at n<\/em>-butane, you’ll see there’s really only two ways to do it. You can take it from C-1 (or C-4), in which case you get a primary alcohol (1-butanol, or “n<\/em>-butanol”). Or you can take it from C-2 (or C-3) in which case you get a secondary alcohol (2-butanol, or “sec<\/em>-butanol”). We sometimes shorten that to “s<\/em>-butanol”.<\/p>\n

\"difference-between-butan-1-ol-and-butan-2-ol-n-butanol-and-sec-butanol\"<\/p>\n

Likewise for the isobutyl skeleton there is two ways to do it. You can replace an H on C-1 (or C-3 or C-4) with OH, in which case you get 2-methyl-1-propanol (“isobutanol”). \u00a0Or you can replace an H on C-2 with OH, and get 2-methyl-2-propanol (“t<\/em>-butanol”). Those are the only two ways to do it!<\/p>\n

\"difference-between-isobutanol-and-tert-butanol-removing-hydrogens-from-isobutane\"<\/p>\n

This applies to other groups too. So if we used Cl instead of OH, we’d have n<\/em>-butyl chloride, s<\/em>-butyl chloride, t<\/em>-butyl chloride, and isobutyl chloride. And if we used some other group, those four names ( n<\/em>-butyl, s<\/em>-butyl, t<\/em>-butyl or isobutyl )\u00a0 all remain the same.<\/p>\n

\"examples-of-different-butyl-chlorides-n-butyl-s-butyl-t-butyl-isobutyl\"<\/div>\n
\n

\u00a0So here’s the punch line for butyl.<\/p>\n

    \n
  1. 1-butyl (“n<\/em>-butyl” where “n<\/em>” stands for “normal”)<\/li>\n
  2. 2-butyl (“s<\/em>-butyl” where “s” stands for “secondary”)<\/li>\n
  3. 2-methyl-1-propyl (“isobutyl”)<\/li>\n
  4. 2-methyl-2-propyl (“t<\/em>-butyl”)<\/li>\n<\/ol>\n<\/div>\n
    What about pentyl? Thankfully, there’s too many possibilities to be limited to this simple system. There’s only one weird case: 2,2-dimethylpropane. We call this “neo<\/strong>pentane”. If you replace an H with a substituent, that becomes the “neopentyl” group.<\/div>\n

    \"neopentane-neopentyl-alcohol-neopentyl-group\"<\/p>\n

    \n

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