Ethyl 2-O-acetyl-4-O-benzoyl-α-L-rhamnopyranosyl-(1->3)-2-O-acetyl-4-O-benzoyl-1-thio-α-L-rhamnopyranoside 、
2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl(1->3)-2,4-di-O-benzoyl-α-L-rhamnopyranosyl 2,2,2-trichloroacetamidate 在
三氟甲磺酸三甲基硅酯 、 4 A molecular sieve 作用下,
以
二氯甲烷 为溶剂,
反应 0.5h,
以88%的产率得到Ethyl 2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl-(1->3)-2,4-di-O-benzoyl-α-L-rhamnopyranosyl-(1->3)-2-O-acetyl-4-O-benzoyl-α-L-rhamnopyranosyl-(1->3)-2-O-acetyl-4-O-benzoyl-1-thio-α-L-rhamnopyranoside