乙酸酐 、 4-methoxybenzoic acid 2-{2'-[3'-(4-methoxybenzoyloxy)-6'-methoxy-3',6'-dihydro-2H-pyran-2'-yl]ethyl}-4,5-dihydroxy-6-methoxytetrahydropyran-3-yl ester 在
吡啶 作用下,
以98%的产率得到4-methoxybenzoic acid (2R,3R,4R,5S,6S)-4,5-diacetoxy-2-{2-[(2S',6R')-3'-(4-methoxybenzoyloxy)-6'-methoxy-3',6'-dihydro-2H-pyran-2'-yl]ethyl}-6-methoxytetrahydropyran-3-yl ester