2-甲氧基丙烯   、                                                                                      
3β-acetoxy-17β-pivaloylandrost-5-ene-19-ol                                                                                                                                                              在
                                                                                                                                                                                 
对甲苯磺酸                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
1,4-二氧六环                                                                                  为溶剂,
                                                                                                                                                                                        以100%的产率得到2,2-Dimethyl-propionic acid (3S,8R,9S,10S,13S,14S,17S)-3-acetoxy-10-(1-methoxy-1-methyl-ethoxymethyl)-13-methyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl ester