(3S,4R,5R)-4-(tert-Butyl-dimethyl-silanyloxy)-3,5-dimethyl-tetrahydro-pyran-2,6-diol   、                                                                                      alkaline earth salt of/the/ methylsulfuric acid                                                                                                                                                              在
                                                                                                                                                                                 4 A molecular sieve                                                                                                                                  作用下,
                                                                                                                                                                                                                            生成                                                 
(3R,4R,5S,6S,7R,8S,9S)-6-(tert-Butyl-dimethyl-silanyloxy)-3,5,7,9-tetramethyl-undeca-1,10-diene-4,8-diol   、                                                                                             (3S,4S,5S,6R)-4-(tert-Butyl-dimethyl-silanyloxy)-3,5-dimethyl-6-((R)-1-methyl-allyl)-tetrahydro-pyran-2-ol