(1R,2S,10S,13S,14R,17S)-17-hydroxy-10,14-dimethyl-5-(4-methylphenyl)-7-oxo-6-oxapentacyclo[11.8.0.02,10.04,9.014,19]henicosa-4,8,19-triene-8-carbonitrile                                                                                                                                                                                                                                                                                                          以68%的产率得到(1R,2S,10S,13S,14R)-10,14-dimethyl-5-(4-methylphenyl)-7,17-dioxo-6-oxapentacyclo[11.8.0.02,10.04,9.014,19]henicosa-4,8,18,20-tetraene-8-carbonitrile