N-芴甲氧羰基-L-苏氨酸五氟苯基酯 、
Acetic acid (3aR,4R,6S,7R,7aR)-7-azido-2,2-dimethyl-6-(2,2,2-trichloro-acetimidoyloxy)-tetrahydro-[1,3]dioxolo[4,5-c]pyran-4-ylmethyl ester 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,
以62%的产率得到(2S,3R)-3-((3aR,4R,6S,7R,7aR)-4-Acetoxymethyl-7-azido-2,2-dimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyran-6-yloxy)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-butyric acid pentafluorophenyl ester