Stereoselective syntheses of 4-oxa diaminopimelic acid and its protected derivatives via aziridine ring opening.

Regio- and stereoselective aziridine ring opening with oxygen nucleophiles derived from serine and threonine provides a route to stereochemically pure 4-oxa-2,6-diaminopimelic acid (oxa-DAP) and its methyl-substituted derivatives. Oxa-DAP is a substrate of DAP epimerase, a key enzyme for biosynthesis of l-lysine and formation of peptidoglycan precursors. Orthogonally protected analogues of lanthionine and beta-methyllanthionine wherein oxygen replaces sulfur were prepared that could be used for solid-supported peptide synthesis to make oxa derivatives of lantibiotics.