hsjordan24

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May 24, 2017
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Pre-Dental
Ring Expansions seem to be giving me a little bit of trouble. I have watched both Chad's and Mike's and only Mike covers it (for 2 seconds) so I assume its not a high yield topic but better safe than sorry. Based on my understanding, it's an SN1 mechanism and occurs to relieve ring strain. I would assume it would mostly likely show up on the DAT in a 3 or 4 membered ring but I could be mistaken. I'm not sure how to identify when it will occur on a given problem. Any help would be appreciated

Thanks!
 

orgoman22

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Ring Expansions seem to be giving me a little bit of trouble. I have watched both Chad's and Mike's and only Mike covers it (for 2 seconds) so I assume its not a high yield topic but better safe than sorry. Based on my understanding, it's an SN1 mechanism and occurs to relieve ring strain. I would assume it would mostly likely show up on the DAT in a 3 or 4 membered ring but I could be mistaken. I'm not sure how to identify when it will occur on a given problem. Any help would be appreciated

Thanks!
Usually...if you have a ring expansion, expect to see a 3 or 4 membered ring with an exocyclic double bond.Often something like HBr or HCl are added. Many other examples do exist however. Refer to an organic text that will easily show you 3 or 4 worked out examples. McMurray and Klein have several.

Hope this helps.

Dr. Romano



ring sdn.png
 
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hsjordan24

hsjordan24

2+ Year Member
May 24, 2017
56
55
Status
Pre-Dental
Usually...if you have a ring expansion, expect to see a 3 or 4 membered ring with an exocyclic double bond.Often something like HBr or HCl are added. Many other examples do exist however. Refer to an organic text that will easily show you 3 or 4 worked out examples. McMurray and Klein have several.

Hope this helps.

Dr. Romano



View attachment 222167
That makes much more sense now thank you very much.
 
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