methyl (2S,4aS,6aR,6aS,6bR,8aR,10S,12aS,14bR)-10-[(2R,3R,4S,5R,6R)-3-acetyloxy-4,5-bis(phenylmethoxy)-6-(phenylmethoxymethyl)oxan-2-yl]oxy-2,4a,6a,6b,9,9,12a-heptamethyl-13-oxo-3,4,5,6,6a,7,8,8a,10,11,12,14b-dodecahydro-1H-picene-2-carboxylate   、                                                                                      
sodium methylate                                                                                                                                                                                                                                                                                                          以90%的产率得到