(3aS,3bR,4R,6aS,7S)-4-(tert-Butyl-dimethyl-silanyloxy)-7-hydroxy-3a,5,5-trimethyl-3,3a,3b,4,5,6,6a,7-octahydro-cyclopenta[a]pentalen-2-one 在
吡啶 、 polyhydrogenfluoride 作用下,
以74%的产率得到(3aβ,3bα,4β,6aα,7α)-3a,3b,4,5,6,6a,7-octahydro-3,3a,5,5-tetramethyl-4α,7-dihydroxycyclopenta<4,5>pentalene-2-one