3β,20β-dihydroxypregn-5-en-18-oic acid 18,20-lactone 3-acetate                                                                                                                                                              在
                                                                                                                                                                                 
sodium methylate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
水                                                                                  为溶剂,
                                                                                                                                                    反应 2.0h,
                                                                                                                以97%的产率得到(3S,8R,9S,10R,13R,14S,17S)-3-Hydroxy-17-((R)-1-hydroxy-ethyl)-10-methyl-1,2,3,4,7,8,9,10,11,12,14,15,16,17-tetradecahydro-cyclopenta[a]phenanthrene-13-carboxylic acid