{"id":8447,"date":"2014-09-02T16:05:58","date_gmt":"2014-09-02T20:05:58","guid":{"rendered":"https:\/\/www.masterorganicchemistry.com\/?p=8447"},"modified":"2026-05-07T09:57:58","modified_gmt":"2026-05-07T14:57:58","slug":"bredts-rule-and-summary-of-cycloalkanes","status":"publish","type":"post","link":"https:\/\/www.masterorganicchemistry.com\/2014\/09\/02\/bredts-rule-and-summary-of-cycloalkanes\/","title":{"rendered":"Bredt’s Rule (And Summary of Cycloalkanes)"},"content":{"rendered":"

Bredt’s Rule: Why Don’t Bridgehead Double Bonds Form?<\/strong><\/p>\n

This post is all about Bredt’s Rule (1924): double\u00a0 bonds cannot be placed at the bridgehead of a\u00a0 bridged ring system. We review the key points from our chapter on cycloalkanes, dive into Bredt’s rule, explain what’s\u00a0 going on in Bredt’s rule (spoiler: poor orbital overlap between p-orbitals)\u00a0 and then (Note 1<\/a>) show that\u00a0 it’s\u00a0 actually more like “Bredt’s Strongly Worded Suggestion” since there\u00a0 are indeed some molecules which possess bridgehead olefins. And we also cover bridgehead amides.<\/p>\n

\"summary<\/a><\/p>\n

Table of Contents<\/strong><\/p>\n

    \n
  1. Cycloalkanes: What We’ve Learned So Far<\/a><\/li>\n
  2. Bredt’s Rule: A Double Bond Cannot Be Placed At The Bridgehead\u00a0 Of A Bridged Ring System<\/a><\/li>\n
  3. Bredt’s Rule Explained:\u00a0 Bridgehead\u00a0 Double Bonds Have\u00a0 Poor Orbital Overlap<\/a><\/li>\n
  4. Summary: Bredt’s Rule<\/a><\/li>\n
  5. Notes<\/a><\/li>\n
  6. Quiz Yourself!<\/a><\/li>\n
  7. (Advanced) References and Further Reading<\/a><\/li>\n<\/ol>\n
    \n

    <\/a>1. What We’ve Learned So Far About Cycloalkanes<\/h2>\n

    At the beginning of this series on cycloalkanes<\/a>\u00a0we saw that carbon’s ability to form rings leads to all kinds of interesting\u00a0consequences that follow logically from the rules of structure and bonding in organic chemistry, but nevertheless would\u00a0have been hard to predict from first principles. Among them, we’ve seen that:<\/p>\n