Synthesis of 1,3-dioxo-hexahydropyrido[1,2-c][1,3]diazepine carboxylates, a new bicyclic skeleton formed by ring expansion-RCM methodology.

A short and elegant synthetic pathway was developed for the synthesis of 1,3-dioxo-hexahydropyrido[1,2-c][1,3]diazepine carboxylates, a new 1,3-diazepan-2,4-dione containing bicyclic moiety, starting from pyroglutamate esters.