(-)-8,8-dimethylbicyclo<5.1.0>oct-2-en-3-one 、
3-methoxy-2-methyl-5,6-dihydro-4H-cyclopenta[b]furan 以80%的产率得到(3aR,3bR,6aS,7aS,7bS,8S)-9-methoxy-7,7,8-trimethyl-1,2,3,5,6,6a,7,7a,7b,8-decahydro-3a,8-epoxycyclopropa[3,4]cyclohepta[1,2-e]inden-4(3bH)-one