(5RS,7SR)-7-t-butyldimethylsilyloxybicyclo[3.3.0]oct-8-en-2-one

(1RS,2SR,5RS,7SR,8SR)-7-t-butyldimethylsilyloxy-3,3,8-trimethylbicyclo<3.3.0>octan-2-ol

(3aR,3bS,4S,6aS,7S)-(-)-3,3a,3b,4,5,6,6a,7-octahydro-4,7-dihydroxy-3a,5,5-trimethylcyclopenta<4.5>pentalen-2-one

(1RS,5RS,7SR,8SR)-7-t-butyldimethylsilyloxy-8-methylbicyclo<3.3.0>octan-2-one