Regioselective reactions of mesyloxymethylazetidinones with nucleophiles I. Cleavage of the azetidinone ring, azetidinone-aziridine ring transformations

The reaction of 4-mesyloxymethylazetidin-2-one derivatives 3 with ammonia and sodium methoxide was investigated. The two electrophilic centers of the substrate reactesuccessively, resulting in cleavage of the lactam bond and formation of a new aziridine ring. The resulting type 6 and 8 aziridinylacetic acid derivatives are related to the novel 2-(aziridin-2-yl)-3-phenylpropionic acid type carboxypeptidase A inhibitors and, as such, potential drug candidates.