2-Ethoxy-5,6,7,8-tetrahydro-7-(3,4,5,6-tetrahydro-2H-thiopyran-3-yl)spiro<4H-chromen-4,1'-cyclopropan>-5-on                                                                                                                                                              在
                                                                                                                                                                                 
sodium hydrogen sulfate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 24.0h,
                                                                                                                以74%的产率得到2-<1-<2-Hydroxy-4-(3,4,5,6-tetrahydr-2H-thiopyran-3-yl)-6-oxo-1-cyclohexen-1-yl>cyclopropyl>essigsaeure-ethylester