NOVEL REARRANGEMENTS OF A 8aH-PYRIDO[1,2-d]THIENO-[2′,3′-b][1,4]THIAZEPINE DERIVATIVE

The reaction of 5-ethoxycarbonyl-3-[1-(4-methylpyridinio)]-4-phenythiopene-2-thiolate with dimethyl acetylenedicarboxylate in refluxing chloroform or tetrahydrofuran afforded the corresponding 10H-pyrrolo[1,2-d]-thieno[2',3'-b][1,4]thiazocines or the 6,8-dithia-2-azatetracyclo[7.3.2.0(2,10)0(3,7)]-tetradeca-Delta(3,7),4,11,13-tetraene derivative. Also, the thermal conversion from the former product to dimethyl (Z)- and (E)-2-[thieno[2',3':2,3][1,4]thiazino-[4,5-a]pyrrol-8-ylidene]succinates was confirmed.