1 / 8

Bredt’s Rule

Bredt’s Rule. (Ok). (Not happening). History and Background. Discovered in 1924 by Julius Bredt while investigating the chemistry of naturally occurring bicyclic terpenes He’s German Bredt also was the first to determine the structure of camphor (1893) Camphor contains a bridged ring.

jpicard
Download Presentation

Bredt’s Rule

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Bredt’s Rule (Ok) (Not happening)

  2. History and Background • Discovered in 1924 by Julius Bredt while investigating the chemistry of naturally occurring bicyclic terpenes • He’s German • Bredt also was the first to determine the structure of camphor (1893) • Camphor contains a bridged ring

  3. What It Says • You can’t have a double bond connected to the bridgehead of a bridged ring system • UNLESS the ring is big enough • Having a double bond as part of the bridgehead would be the equivalent of having a trans double bond on the ring • This would create massive angular strain on the ring

  4. What It Says

  5. H H B r H H H H H 100% What It’s Good For • Good for predicting the product resulting from elimination reactions of bridged ring systems Bredt’s Rule NaOEt EtOH + 110 oC 0%

  6. Exceptions • 8-membered rings with double bonds at the bridgehead can be isolated • Less than 7, extremely difficult to find said character

  7. Exceptions • Anti-Bredt Molecules • 7 membered (or less) rings that do have double bonds located at the bridgehead • Example: 2-quinuclidonium tetrafluoroborate

  8. Exceptions

More Related