Regio- and stereo-specific synthesis of threo-3-amino-2-hydroxy-acids, novel amino-acids contained in aminopeptidase inhibitors of microbial origin

Abstract

threo-3-Amino-2-hydroxy-4-phenylbutanoic acid, a novel amino-acid contained in bestatin, an inhibitor of aminopeptidase B and leucine aminopeptidase, and threo-3-amino-2-hydroxy-5-methylhexanoic acid, a novel amino-acid contained in amastatin, an inhibitor of aminopeptidase A and leucine aminopeptidase, have been synthesized from cis- and trans-2-olefinic acids via regiospecific ring-opening of cis-2,3-epoxy-acids by ammonia. Direct hydroxyamination of the 2-olefinic acids, however, gave 2-amino-3-hydroxy-acids as the major products.