Reaction of methyl 2-methylidene-3-oxolup-20(29)-en-28-oate with triphenylphosphonium trifluoromethanesulfonate

Abstract

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.