Preparation of New Nitrogen-Bridged Heterocycles. 29. Reinvestigation on the Dehydrogenation Reaction of 5,5a-Dihydropyridothienothiazine Derivatives

Article abstract of DOI:10.1246/bcsj.65.1244

Reactions of the title compounds with 2,3-dichloro-4,5-dicyano-p-benzoquinone were reinvestigated; it was found that the corresponding products were not the ring-contracted and rearranged thieno<2,3-b>indolizines, as described previously by us, but were o