Synthesis of cyanoketophosphoranes, precursors of β-amino-α-keto-esters from UNCAs

Abstract

Cyanomethylene triphenylphosphoranes of N-protected amino acids were synthesized from the corresponding N-urethane protected α-amino acid N-carboxyanhydrides (UNCAs) by reaction with cyanomethyltriphenylphosphonium chloride in good yields. These compounds are precursors of α-keto esters which are candidates for mimicking the tetrahedric transition state in enzyme inhibitors.