Hoffman rearrangement question

[BiomajorPreDent]

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Hey, I was doing achiever and theres a question about the hoffman rearrangement.

i didnt see it in the ADA's outline or named reactions..

so I was wondering if its fair game or has anyone seen it?

I mean I know I should just memorize it anyway since we dont even need to know mechanisms..but Id rather not worry about it if I dont have to

ps: the named rxns ive got down are

williamson ether synthesis
wittig
diels alder
aldol
wolff kishner
clemmensen

am I missing anything?

 

[joonkimdds]

I wouldn't follow any outlines, I would just know everything.

 

[peyman2002]

Hey, I was doing achiever and theres a question about the hoffman rearrangement.

i didnt see it in the ADA's outline or named reactions..

so I was wondering if its fair game or has anyone seen it?

I mean I know I should just memorize it anyway since we dont even need to know mechanisms..but Id rather not worry about it if I dont have to

ps: the named rxns ive got down are

williamson ether synthesis
wittig
diels alder
aldol
wolff kishner
clemmensen

am I missing anything?

yea dont know, Im wondering about that too

 

[gentile1225]

• aldol, mixed aldol
• maybe clasien
• esterification, a common question is when there is a radioactively labeled Oxygen and you need to know that the O found in the ester (resulting from i.e. carboxy and alcohol), between the carbonyl carbon and -R group comes from the alcohol.
• obviously sn1, sn2, e1, e2
• malonic ester & acetoacetic ester synthesis are rare, but fair game
• as well as michael-robbinson, dieckmann
• alpha halogenation (carboxy acids)
• ozonlysis (cleaving c=c to form two c=o bonds)

hope this helps. check out destroyer road moaps, they basically have every reaction that is a possibilty.

 

[BiomajorPreDent]

oh ya, about those roadmaps

This is not a complicated reaction but I just dont understand it..

on roadmap 2 (its also in beginning of roadmap 3)

on the bottom left and on the top left, what is the Br2/hv addition?

On the bottom of roadmap 2 its alone and on the top it has peroxides ROOR or NBS..i cant find those in my ochem book

what exactly is going on with that?

 

[jbrenn4]

Br2/hv Br substitute a tertiary H...Br is very regoselective......NBS adds Br to the allylic carbon...and peroxides usually make a reaction go anti markovnikov

 

[nze82]

Know this reaction! I had two Hoffman Rearrangement reactions on my test! Don't try to find out which reactions you shouldn't know! KNOW AS MANY RXNs AS POSSIBLE. Any reaction is fair game as long as it's mentioned somewhere in some college O-chem text book!