Synthesis of D-Ala--D-Ala analogues with postulated antibacterial activity

The syntheses of the L,L- and D,D-stereoisomers of N-phenoxyacetyl-X-alanine in which X=His, Tyr, or Lys, are described. The antibacterial activity of some of the peptide derivatives and their synthetic intermediates have been examined. Some of the intermediates exhibited moderate activity against viridans streptococci, enterococci and Streptococcus agalactiae. None of the compounds were active against beta-lactamase producing bacteria or served as beta-lactamase inhibitors.