Utilization of Protopine and Related Alkaloids. XI. Photolysis of 7, 8-Dimethoxy-2-methyl-3-(4', 5'-methylenedioxy-2'-vinyl-phenyl) isocarbostyril and Its Application to the Preparation of Oxychelerythrines

Abstract

Photolysis of the isocarbostyril (5) gives predominantly the regioisomeric dimers (7) and (8). Attempts to trap the initial photo-product (14) with dienophiles are made and the formation mechanisms of the resulting products are discussed. The 4b, 12-epoxyimino compound (18) resulted from trapping with nitrosobenzene is smoothly converted into oxychelerythrines.