3,6-di-O-acetyl-2-azido-2-deoxy-4-O-(methyl 2,3-di-O-benzyl-4-O-levulinoyl-β-D-glucopyranosyluronato)-α-D-glucopyranosyl bromide 、
methyl 3,6-di-O-benzyl-2-(benzyloxycarbonylamino)-2-deoxy-4-O-(methyl 2,3-di-O-benzyl-β-D-glucopyranosyluronato)-α-D-glucopyranoside 在
molecular sieve 、
silver trifluoromethanesulfonate 作用下,
以
二氯甲烷 为溶剂,
以20%的产率得到