甲醇 、
2-[(3aR,4R,6R,9Z,10aS)-6,9-dimethyl-4-[(E)-2-methylbut-2-enoyl]oxy-3-methylidene-2,8-dioxo-3a,4,5,10a-tetrahydrofuro[2,3-e]oxonin-6-yl]acetic acid 在
硫酸 作用下,
反应 10.0h,
生成 (E)-2-Methyl-but-2-enoic acid (Z)-(3aR,4R,6R,10aS)-6-methoxycarbonylmethyl-6,9-dimethyl-3-methylene-2,8-dioxo-2,3,3a,4,5,6,8,10a-octahydro-furo[2,3-e]oxonin-4-yl ester