Phosphorylation of methyl 2-methylidene-3-oxolup-20(29)-en-28-oate with triphenylphosphonium trifluoromethanesulfonate in methylene chloride at 20°C afforded 90% of a γ-oxoalkylphosphonium salt containing a terpenoid fragment, [28-methoxy-3,28-dioxolup-20(29)-en-2-ylmethyl]triphenylphosphonium trifluoromethanesulfonate, as a mixture of two epimers (2S/2R) at a ratio of 2: 1.
将三亚甲基
三氟甲磺酸三苯基phosph在20°C的条件下用
二氯甲烷中的2-亚甲基-3-氧甲基20-20(29)-en-28-
膦酸酯进行
磷酸化,得到90%的含有
萜类片段的[-28-甲氧基- 3,28-dioxolup-20(29)-en-2-yl甲基]三苯基phosph
三氟甲磺酸盐,为两种差向异构体(2S / 2R)的混合物,比率为2:1。