(2R,3R,4R,5S,6R)-6-Azidomethyl-3-(9H-fluoren-9-ylmethoxycarbonylamino)-4,5-dihydroxy-tetrahydro-pyran-2-carboxylic acid 、
二甲醇缩甲醛 在
phosphorus pentoxide 作用下,
生成
(2R,3R,4R,5R,6R)-6-Azidomethyl-3-(9H-fluoren-9-ylmethoxycarbonylamino)-4,5-bis-methoxymethoxy-tetrahydro-pyran-2-carboxylic acid methoxymethyl ester