Ethyl 1'-[2-(3,4-dimethoxyphenyl)ethyl]-2',3'-dioxospiro[1,3-dioxolane-2,5'-4,6-dihydroindole]-3'a-carboxylate 在
磷酸 作用下,
反应 1.5h,
以10%的产率得到rac-ethyl (8aR,9R,11aR,11bS)-8a-hydroxy-2,3-dimethoxy-8,10-dioxo-5,6,8a,9,10,11-hexahydro-9,11b-methanocyclopenta[3,4]pyrrolo[2,1-a]isoquinoline-11a(8H)-carboxylate