sodiodimethylmalonate 、 methyl (3aR*,4R*)-4-(2-bromoethyl)-2,3,3a,4,5,6-hexahydro-5,5-dimethyl-2-oxo-1-pentalenecarboxylate 以
四氢呋喃 为溶剂,
以70%的产率得到2-((3aR,4S,6aS)-4-Methoxycarbonyl-2,2-dimethyl-5-oxo-hexahydro-1,4-ethano-pentalen-3a-yl)-malonic acid dimethyl ester