1,3-AMINO ALCOHOLS FROM 4-AMINO-1-AZA DIENES - DIASTEREOSELECTIVE AND ENANTIOSELECTIVE APPROACH TO THE 4 DIASTEREOISOMERS OF THE N-TERMINAL AMINO-ACID COMPONENT OF NIKKOMYCIN-B AND NIKKOMYCIN-B(X)

A strategy that entails the preparation of 1,3-amino alcohols from 4-amino-1-aza dienes is used to synthesize the four diastereoisomeric lactones of the N-terminal amino acid moiety of nikkomycins B and B(X) in a diastereo- and enantioselective manner. Thus, enantiomerically pure beta-amino ketones anti-13 and syn-13 were synthesized starting from the 4-amino-1-aza diene 10 and (R)-O-benzyllactic aldehyde via the corresponding dihydro- and tetrahydropyrimidines. These beta-amino ketones were further converted into the lactones 22-25 with high diastereoselectivity through their 1,3-amino alcohol derivatives.