A new catalytic enantiospecific approach to the synthesis of epibrassinosteroids (and other polyhydroxylated steroids) regiospecifically labeled by heavy isotopes of hydrogen is reported. Chlorocarbonate, efficiently synthesized from α-hydroxy ketone by a reaction with triphosgene, undergoes reductive tritium dechlorination catalyzed by the [Pd0]/Et3N system, providing 24-[3β-3H]epicastasterone and
报道了一种新的催化对映体特异性方法,用于合成由氢的重同位素区域标记的表油素类
固醇(和其他多羟基化类
固醇)。
氯,通过与
三光气的反应由α羟基酮有效地合成,经历还原脱
氯氚催化由[
钯0 ] / ET 3 N制,提供24- [3β- 3 H] epicastasterone和24- [3β- 3 ħ ]
表油菜素内酯,分别具有良好的产率和高的比活度(5.8Ci / mmol; per富集度为每个分子20%)。