4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-phthalimido-α/β-D-galactopyranosyl bromide   、                                                                                      
pent-4-enyl 3-O-allyl-6-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranoside                                                                                                                                                              在
                                                                                                                                                                                 4 A molecular sieve   、                                                                                                  silver perchlorate   、                                                                                                  silver carbonate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 10.0h,
                                                                                                                以17%的产率得到pent-4-enyl 4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranosyl-(1->4)-3-O-allyl-6-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranoside