dihydronaphthopyran derivatives were obtained in good yield by the regio‐ and stereoselective annulation of ortho‐naphthoquinone methides with allyl silanes. The ortho‐naphthoquinone methides were generated in situ from 1‐siloxymethyl‐1,4‐epoxy‐1,4‐dihydronaphthalenes under FeCl3 catalysis (see scheme; allyl‐TMS=allyltrimethylsilane, TBS=tert‐butyldimethylsilyl, TMS=trimethylsilyl).
通过邻-
萘醌甲基化物与烯丙基
硅烷的区域和立体选择性环化,可得到高收率的药学上有用的二氢
萘并
吡喃衍
生物。的邻位从原位产生-naphthoquinone甲基化物1-甲
硅烷氧基-1,4-环氧-1,4-二氢
萘下的FeCl 3催化(参见方案;烯丙基TMS =烯丙基三甲基
硅烷,TBS =叔丁基二,TMS =三甲基甲
硅烷)。