The preparation of optically active a-aspartylpeptides which are entirely free from the corresponding p-isomers is not easily accomplished The two most important methods so far devised for their synthesis have been worked out by In the first method benzyloxycarbonyl-L- aspartic anhydride was coupled with an amino acid ester's2 whereby a mixture of CY-and 6- aspartyldipeptides was produced which was then separated by repeated extraction with ...
