2-Methyl-3-oxo-butyric acid (2S,3R,4S,5R,6R)-4,5-bis-benzyloxy-6-benzyloxymethyl-2-phenylsulfanyl-tetrahydro-pyran-3-yl ester   、                                                                                      
碘甲烷                                                                                                                                                              在
                                                                                                                                                                                 
potassium tert-butylate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
四氢呋喃                                                                                  为溶剂,
                                                                                                                                                    反应 0.5h,
                                                                                                                生成                                                 2,2-Dimethyl-3-oxo-butyric acid (2S,3R,4S,5R,6R)-4,5-bis-benzyloxy-6-benzyloxymethyl-2-phenylsulfanyl-tetrahydro-pyran-3-yl ester