1,2-Asymmetric Induction in the Zwitterionic Claisen Rearrangement of Allylamines

Article abstract of DOI:10.1021/jo00117a032

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 γ,δ-unsaturated amides were cyclized to the corresponding optically active γ-butyrolactones, which are useful intermediates in natural product synthesis.