A Novel Route to Diastereomerically Pure (<i>E</i>)‐Alkene Dipeptide Isosteres from β‐Aziridinyl‐α,β‐enoates by Treatment with Organocopper Reagents

Abstract

Why do enoates 1 and 2 give the same product 3 in their reaction with organocopper reagents? The absolute configuration at the alkylated α position and the (E) configuration of the biologically important N-protected dipeptide isostere 3 reflect the preferred conformation of substrates 1 and 2, which in turn is controlled by allylic 1,3 strain.