The Compounds Limits of Detection, Molecules of Only One Chirality Synthesis of (+)-Monomorine Using a 5-Endo-Trig Cyclization Strategy

A Strategy for the Synthesis of (+)-Monomorine Using 5-Endo-Trig Cyclization

Abstract

We have developed a general strategy for thesynthesis of 2,5-syn disubstituted pyrrolidines that is based on themulti-faceted reactivity of the sulfone moiety and a 5-endo-trig cyclisation.This methodology was applied to the synthesis of indolizidine alkaloidmonomorine I. Two factors were key to the success of this endeavour; the firstwas the choice of nitrogen protecting group whilst the second was theconditions for the final stereoselective amination step. Employing acombination of different protecting groups and an intramolecular reductiveamination reaction we were able to prepare (+)-monomorine I in just 11 stepsfrom commercially available D-norleucine in a completely stereoselectivemanner.