(4aS,5S,6S,8aS)-5,8a-dimethyl-6-hydroxy-5-(3-hydroxypropyl)decahydronaphthalen-1-one-1-ethylene acetal                                                                                                                                                              在
                                                                                                                                                                                 2,2,6,6-tetramethyl-piperidine-N-oxyl   、                                                                                                  
碘苯二乙酸                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 6.0h,
                                                                                                                以95%的产率得到(4'aS,6'aS,10'aS,10'bS)-6'a,10'b-dimethylspiro[1,3-dioxolane-2,7'-2,4a,5,6,8,9,10,10a-octahydro-1H-benzo[f]chromene]-3'-one