2,4,6-tri-O-benzyl-D-mannono-1,5-lactone 、
(2R,3S,4S,5R,6R)-3,4,5-Tris-benzyloxy-2-((2R,3R,4S,5S)-3,5-bis-benzyloxy-2-benzyloxymethyl-6-methylene-tetrahydro-pyran-4-yloxy)-6-(4-methoxy-benzyloxymethyl)-2-methyl-tetrahydro-pyran 在
甲烷磺酸 、 4 A molecular sieve 作用下,
以
二氯甲烷 为溶剂,
以36%的产率得到(3S,4S,5R,6R)-4-[(2R,3S,4S,5R,6R)-4-[(2R,3S,4S,5R,6R)-6-[(4-methoxyphenyl)methoxymethyl]-2-methyl-3,4,5-tris(phenylmethoxy)oxan-2-yl]oxy-2-methyl-3,5-bis(phenylmethoxy)-6-(phenylmethoxymethyl)oxan-2-yl]oxy-3,5-bis(phenylmethoxy)-6-(phenylmethoxymethyl)oxan-2-one