Stereocontrolled Synthesis of Erythro N-Protected α-Amino Epoxides and Peptidyl Epoxides.

N-protected α-amino epoxides of erythro configuration, derived from α-amino acids, were synthesized in a stereoselective manner. The erythro (2S,3S) configu- ration was achieved by the synthetic sequence: amino acid → haloketone → halohydrin → epoxide. A mechanistic explanation for the observed stereoselectivity is presented. This stereoselective synthetic approach was applied to the synthesis of a variety of short peptidyl epoxides, bearing a predefined absolute configuration of the chiral epoxide moiety.