Enhanced trans diastereoselection in the allylation of cyclic chiral N-acyliminium ions.: Synthesis of hydroxylated indolizidines

A short synthesis of hydroxylated indolizidines is reported. The key steps were the allylation of chiral cyclic N-acyliminium ions derived from malic and tartaric acids. followed by ring-closing metathesis. (C) 2001 Elsevier Science Ltd. All rights reserved.