Acetic acid 2-((S)-2-acetoxy-propyl)-5,7,8-trimethyl-1,4-dioxo-1,4-dihydro-phenanthren-3-yl ester 在
MeOH-Lsg 、
potassium hydrogencarbonate 作用下,
反应 2.0h,
以73%的产率得到(S) Plectranthon B ( = (S)-<2-(3-Hydroxy-5,7,8-trimethyl-1,4-dioxophenanthren-2-yl)-1-methylethyl>-acetat)