5-[(3S,5S,8R,9S,10S,13R,14S,17R)-17-((R)-1,5-Dimethyl-hexyl)-10,13-dimethyl-hexadecahydro-cyclopenta[a]phenanthren-3-yl]-4-hydroxy-pent-2-ynoic acid ethyl ester                                                                                                                                                              在
                                                                                                                                                                                 
chromium(VI) oxide   、                                                                                                  
硫酸                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
四氢呋喃   、                                                                                         
丙酮                                                                                  为溶剂,
                                                                                                                                                                                        以88%的产率得到ethyl 5-[(3S,5S,8R,9S,10S,13R,14S,17R)-10,13-dimethyl-17-[(2R)-6-methylheptan-2-yl]-2,3,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl]-4-oxopent-2-ynoate