2-甲氧基丙烯 、 (3R,5R,7S)-8-[(4S,6R)-2-(4-methoxyphenyl)-5,5-dimethyl-6-[(2R,4S,6S)-2,4,6,8-tetrahydroxy-3,3,7,7-tetramethyloctyl]-1,3-dioxan-4-yl]-2,2,6,6-tetramethyloctane-1,3,5,7-tetrol 在
对甲苯磺酸 作用下,
以
N,N-二甲基甲酰胺 为溶剂,
反应 4.0h,
以90%的产率得到(4SR,6RS)-2-(4-methoxyphenyl)-5,5-dimethyl-4-[(4SR,6RS)-2,2,5,5-tetramethyl-6-{(4SR,6RS)-2,2,5,5-tetramethyl-6-[(4RS)-2,2,5,5-tetramethyl-1,3-dioxan-4-ylmethyl]-1,3-dioxan-4-ylmethyl}-1,3-dioxan-4-ylmethyl]-6-[(4SR)-2,2,5,5-tetramethyl-1,3-dioxan-4-...]