(3aR,5aS,8S,9aS,9bS)-5a-Acetoxymethyl-8-hydroxy-2,2-dimethyl-3a,5a,6,7,8,9,9a,9b-octahydro-naphtho[1,2-d][1,3]dioxole-9-carboxylic acid methyl ester                                                                                                                                                                                                                                                                                                          以75%的产率得到(3aR,5aS,9aS,9bS)-5a-Acetoxymethyl-2,2-dimethyl-8-oxo-3a,5a,6,7,8,9,9a,9b-octahydro-naphtho[1,2-d][1,3]dioxole-9-carboxylic acid methyl ester