(E)-(2R,5S,6S,7R,8R)-6-(tert-Butyl-dimethyl-silanyloxymethyl)-5,7-dihydroxy-9-(4-methoxy-benzyloxy)-2,4,8-trimethyl-non-3-enoic acid ethyl ester 、
2,2-二甲氧基丙烷 在
对甲苯磺酸 作用下,
以
二氯甲烷 为溶剂,
反应 1.0h,
以82%的产率得到(E)-(R)-4-{(4S,5S,6R)-5-(tert-Butyl-dimethyl-silanyloxymethyl)-6-[(R)-2-(4-methoxy-benzyloxy)-1-methyl-ethyl]-2,2-dimethyl-[1,3]dioxan-4-yl}-2-methyl-pent-3-enoic acid ethyl ester