5,6-de-epoxy-5β,6α-(oxyethylene-2'-thio) withaferin A 、
乙酸酐 在
吡啶 作用下,
以80%的产率得到[(2R)-2-[(1S)-1-[(1S,2R,6S,7R,12S,14S,15S,18R,19S)-6-acetyloxy-2,19-dimethyl-3-oxo-8-oxa-11-thiapentacyclo[12.7.0.02,7.07,12.015,19]henicos-4-en-18-yl]ethyl]-4-methyl-6-oxo-2,3-dihydropyran-5-yl]methyl acetate