Phthalic acid 1-[(2S,3R,4S,5S,6R)-6-(tert-butyl-diphenyl-silanyloxymethyl)-4,5-dihydroxy-2-methoxy-tetrahydro-pyran-3-yl] ester 2-((2R,3R,4S,5S,6R)-3,4,5-trimethoxy-6-phenylsulfanyl-tetrahydro-pyran-2-ylmethyl) ester                                                                                                                                                              在
                                                                                                                                                                                 
N-碘代丁二酰亚胺   、                                                                                                  
三氟甲磺酸   、                                                                                                  4 A molecular sieve                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                                                        以76%的产率得到(1R,3S,4R,5R,7S,8R,20R,21R,22S,23S)-5-[[tert-butyl(diphenyl)silyl]oxymethyl]-4-hydroxy-7,21,22,23-tetramethoxy-2,6,9,18,24-pentaoxatetracyclo[18.3.1.03,8.011,16]tetracosa-11,13,15-triene-10,17-dione