ethyleneketal of 8,13a-(2'-oxopropano)-13-hydroxy-9,10-dimethoxy-2,3-methylenedioxy dibenzo-(a,g)-quinolizine 在
吡啶 、
chromium(VI) oxide 作用下,
反应 7.0h,
以240 mg的产率得到9',10'-dimethoxyspiro[[1,3]dioxolane-2,16'-[8,13a]propano[1,3]dioxolo[4,5-g]isoquinolino[3,2-a]isoquinoline]-5',6',13'(8'H)-trione