methyl 4,4-diethoxycyclobut-1-ene-1-carboxylate 、
[1-(4,4-Dimethyl-cyclopent-1-enyl)-vinyloxy]-trimethyl-silane 以72%的产率得到(2aS,7aR,7bS)-1,1-Diethoxy-6,6-dimethyl-4-trimethylsilanyloxy-2a,3,5,6,7,7a-hexahydro-1H,2H-cyclobuta[e]indene-7b-carboxylic acid methyl ester