Imminium ion chemistry at C-2 of pyroglutamates: Unexpected formation of 1,4-Methano-3-oxa-6-t-butyl-7-azabicyclo[7.3.0]decan-2,8-dione

摘要

alpha-Bromination of the cyclically protected S-pyroglutamic acid, its subsequent reactions with nucleophillic reagents via corresponding N-acylimminium intermediate is described. Natural alpha-amino acids are useful as starting material for the synthesis of enantiomerically pure compounds, the single chiral center providing a cheap source of chirality~1.