The diastereoselective synthesis of Pro-Phe phosphinyl dipeptide isosteres in protected form was achieved by starting from optically active 1,1-diethoxyethyl(aminomethyl)phosphinate. Our methodology involves diastereoselective alpha-alkylation and beta'-alkylation of phosphinate derivatives with an asymmetric center at the phosphorus atom. (C) 2012 Elsevier Ltd. All rights reserved.