Regiospecific ring-opening reactions of beta-aziridinyl alpha,beta-enoateswith acids: application to the stereoselective synthesis of a couple of diastereoisomeric (E)-alkene dipeptide isosteres from a single beta-aziridinyl alpha,beta-enoate and to the convenient preparation of amino alcohols bearing alpha,beta-unsaturated ester groups

Regio- and stereo-selective ring-opening reactions of N-(2,4,6-trimethylphe nylsulfonyl)-gamma,delta-cis- or - trans-gamma,delta-epimino (E)-alpha,beta -enoates with acids such as methanesulfonic acid (MSA) or trifluoroacetic a cid (TFA) have been found. These ring-opening reactions are useful for the stereoselective synthesis of a couple of diastereomeric (E)-alkene dipeptid e isosteres from a single substrate of gamma,delta-epimino (E)- alpha,beta- enoate, and for the convenient preparation of delta-aminated gamma-hydroxy alpha,beta-enoates.