4-甲氧基-3-氧代-1,3-二氢异苯并呋喃-1-腈 、 (+/-)-(4RS,5SR)-5',5-dimethoxy-2,2,5-trimethyl-3',4'-dihydrospiro<1,3dioxolan-4,2'(1'H)-naphthalen>-8'(5'H)-one 在
lithium diisopropyl amide 作用下,
生成
(+/-)-(4RS,5SR)-4',11'-dimethoxy-6'-hydroxy-2,2,5-trimethyl-9',10'-dihydrospiro<1,3-dioxolan-4,8'(7'H)-naphthacene>-5',12'-dione