Benzoic acid (3S,5S,8R,9S,10S,12R,13S)-3-acetoxy-17-((S)-1,5-dimethyl-2-oxo-hex-5-enyl)-10,13-dimethyl-2,3,4,5,6,7,8,9,10,11,12,13-dodecahydro-1H-cyclopenta[a]phenanthren-12-yl ester 、
2,2-dibromo-1,3-propanediol 在
scandium tris(trifluoromethanesulfonate) 、
原甲酸三甲酯 作用下,
以
乙腈 为溶剂,
生成 Benzoic acid (3S,5S,8R,9S,10S,12R,13S)-3-acetoxy-17-[(S)-2-(2,2-dibromo-3-hydroxy-propoxy)-2-hydroxy-1,5-dimethyl-hex-5-enyl]-10,13-dimethyl-2,3,4,5,6,7,8,9,10,11,12,13-dodecahydro-1H-cyclopenta[a]phenanthren-12-yl ester