(3R,4S,5R,6R)-3,4,5-Tris-benzyloxy-6-((2S,3R,4S,5R,6R)-3,4,5-tris-benzyloxy-6-hydroxymethyl-2-methyl-tetrahydro-pyran-2-yloxymethyl)-tetrahydro-pyran-2-one 、 (2S,3R,4S,5R,6R)-3,4,5-Tris-benzyloxy-6-(4-methoxy-benzyloxymethyl)-2-methyl-2-((2R,3R,4S,5R)-3,4,5-tris-benzyloxy-6-methylene-tetrahydro-pyran-2-ylmethoxy)-tetrahydro-pyran 在
三氟甲磺酸 、 4 A molecular sieve 作用下,
以
二氯甲烷 为溶剂,
生成