、                                                                                      
allyl O-(2,3,4-tri-O-benzyl-α-D-glucopyranosyl)-(1<*>6)-O-2,3,6-tri-O-benzyl-α-D-glucopyranoside                                                                                                                                                              在
                                                                                                                                                                                 4 A molecular sieve   、                                                                                                  
氰化汞   、                                                                                                  mercury dibromide                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
1,2-二氯乙烷                                                                                  为溶剂,
                                                                                                                                                    反应 6.0h,
                                                                                                                以83%的产率得到Chloro-acetic acid (2R,3R,4S,5R,6S)-6-[(2R,3R,4S,5R,6S)-6-((2R,3R,4S,5R,6R)-6-allyloxy-3,4,5-tris-benzyloxy-tetrahydro-pyran-2-ylmethoxy)-3,4,5-tris-benzyloxy-tetrahydro-pyran-2-ylmethoxy]-3,4,5-tris-benzyloxy-tetrahydro-pyran-2-ylmethyl ester