From beta-lactams to alpha- and beta-amino acid derived peptides

The potential of beta-lactams as intermediates for the access to alpha- and beta-amino acid-derived peptides is shortly reviewed, with major focus on the technologies developed in our group. The two general strategies lie, on one side, in the oxidative ring expansion of 3-hydroxy beta-lactams to N-c arboxy alpha-amino acid anhydrides or Leuch's anhydrides and subsequent cou pling with alpha-amino acid esters and, on the other side, in the nucleophi lic ring opening of N-Boc-beta-lactams. Both approaches have been successfu lly applied to the synthesis of alpha,beta-diamino acid, alpha-amino-beta-h ydroxy acid, polyhydroxylated alpha-amino acid, alpha,alpha-disubstituted a lpha-amino acid, beta-amino acid, beta-amino-alpha-hydroxy acid and beta,be ta-disubstituted beta-amino acid derived peptides. Because of the mild reac tion conditions needed for the above transformations and the highly stereos elective procedures employed for the construction of the starting beta-lact am ring, the whole process allows the production of optically pure final pr oducts.