6β-methoxy-3α,5-cyclo-5α-23,24-bisnorcholan-22-carbaldehyde   、                                                                                      
1-三苯基膦-2-丙酮                                                                                                                                                                                              以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                                                        以70%的产率得到(E)-(R)-6-((1aR,3aR,3bS,5aR,6R,8aS,8bS,10R,10aR)-10-Methoxy-3a,5a-dimethyl-hexadecahydro-cyclopenta[a]cyclopropa[2,3]cyclopenta[1,2-f]naphthalen-6-yl)-hept-3-en-2-one