prenylmagnesium bromide 、 以59%的产率得到(5''S,11'S,17'R)-10',13'-dimethyl-11'-(3-methylbut-2-en-1-yl)-1',4',7',8',9',10',11',12',13',14',15',16'-dodecahydro-2'H-trispiro[[1,3]dioxolane-2,3'-cyclopenta[a]phenanthrene-17',4''-[1,3]dioxolane-5'',4'''-[1,3]dioxolan]-11'-ol