1,2-Asymmetric Induction in the Zwitterionic Claisen Rearrangement of Allylamines
摘要:
A zwitterionic Claisen rearrangement has been developed for optically active N-allylpyrrolidines using a two-phase system. The inherent-1,2 asymmetric induction was investigated for the generation of a new C-C bond adjacent to a chiral C-O function. The reaction with acetyl chloride led to a small diastereomeric excess, whereas the rearrangement with propionyl chloride proceeded with a high simple and a high induced diastereoselection. The resulting gamma,delta-unsaturated amides were cyclized to the corresponding optically active gamma-butyrolactones, which are useful intermediates in natural product synthesis.
1,2-Asymmetric Induction in the Zwitterionic Claisen Rearrangement of Allylamines
作者:Udo Nubbemeyer
DOI:10.1021/jo00117a032
日期:1995.6
A zwitterionic Claisen rearrangement has been developed for optically active N-allylpyrrolidines using a two-phase system. The inherent-1,2 asymmetric induction was investigated for the generation of a new C-C bond adjacent to a chiral C-O function. The reaction with acetyl chloride led to a small diastereomeric excess, whereas the rearrangement with propionyl chloride proceeded with a high simple and a high induced diastereoselection. The resulting gamma,delta-unsaturated amides were cyclized to the corresponding optically active gamma-butyrolactones, which are useful intermediates in natural product synthesis.
Diastereoselective Zwitterionic Aza-Claisen Rearrangement: The Synthesis of Bicyclic Tetrahydrofurans and a Total Synthesis of (+)-Dihydrocanadensolide
作者:Udo Nubbemeyer
DOI:10.1021/jo9600464
日期:1996.1.1
The zwitterionic Claisen rearrangement of optically-active N-allyl pyrrolidines and various acid chlorides proceeds with high simple diastereoselection (internal asymmetric induction) and high 1,2-asymmetric induction, generating a new C-C bond adjacent to a chiral C-O function. The resulting gamma,delta-unsaturated amides were cyclized to the corresponding opticallyactive gamma-butyrolactones, which