UNEXPECTED FORMATION OF THIINO[3',4':4,5]OXAZOLO[1,3-b]-[1,3]OXAZEPINE DERIVATIVES

摘要

The reactions of pyridinium 2-alkylthio-l-benzoyl-2-thioxoethylides with dimethyl acetylenedicarboxyate in THF at the reflux temperature afforded the unexpected products, dimethyl 2-alkylthio-4a-phenyl-4aH,5aH-thiino-[3',4':4,5]oxazolo[1,3-b)][1,3]oxazepine-3,4-dicarboxylates, together with dimethyl 10aH-4-alkylthio-5-benzoy lpyrido[1,2-d] [1,4]thiazepine-1,2-dicarboxylates.