drevogenin A acetate                                                                                                                                                              在
                                                                                                                                                                                 sodium tetrahydroborate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲醇                                                                                  为溶剂,
                                                                                                                                                    反应 1.0h,
                                                                                                                以24.9 mg的产率得到3-Methyl-butyric acid (3S,8R,9S,10R,11S,12S,13S,14S,17S)-3,11-diacetoxy-14-hydroxy-17-((R)-1-hydroxy-ethyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-12-yl ester