O-ethyl S-[2-azido-6-O-benzyl-2-desoxy-3,4-O-isopropylidene-α-D-galactopyranosyl-(1->4)-3-O-acetyl-2-azido-6-O-benzyl-2-desoxy-α-D-galactopyranosyl]xanthate 、 methyl O-(3-O-acetyl-2-azido-6-O-benzyl-2-desoxy-α-D-galactopyranosyl)-(1->4)-O-(3-O-acetyl-2-azido-6-O-benzyl-2-desoxy-α-D-galactopyranosyl)-(1->4)-3-O-acetyl-2-azido-6-O-benzyl-2-desoxy-α-D-galactopyranoside 在
de triflate de dimethyl (methylthio) sulfonium 作用下,
以
二氯甲烷 为溶剂,
反应 3.0h,
以57%的产率得到[(2S,3R,4R,5R,6R)-5-[(2R,3R,4R,5R,6R)-5-[(2R,3R,4R,5R,6R)-5-[(2R,3R,4R,5R,6R)-5-[[(3aR,4R,6R,7R,7aR)-7-azido-2,2-dimethyl-4-(phenylmethoxymethyl)-4,6,7,7a-tetrahydro-3aH-[1,3]dioxolo[4,5-c]pyran-6-yl]oxy]-4-acetyloxy-3-azido-6-(phenylmethoxymethyl)oxan-2-yl]oxy-4-acetyloxy-3-azido-6-(phenylmethoxymethyl)oxan-2-yl]oxy-4-acetyloxy-3-azido-6-(phenylmethoxymethyl)oxan-2-yl]oxy-3-azido-2-methoxy-6-(phenylmethoxymethyl)oxan-4-yl] acetate