Ozonolysis of cholesterol and other Δ5-steroids in the presence of alcohols: a revised mechanism and hydroperoxide structure of the solvent-participated product, confirmed by X-ray analysis
作者:Zdzisław Paryzek、Urszula Rychlewska
DOI:10.1039/a702633a
日期:——
The structure of the product formed in the course of the reaction of cholesterol acetate and other Δ5-steroids with ozone in alcohol-containing solvents has been revised. The solvent-participated products are hydroperoxides, 5α-hydroperoxy-7α-alkoxy-5α-B-homo-6-oxasteroids 3 and not the previously claimed cyclic hemiperacetals, 5α-hydroxy-7a-alkoxy-B-dihomo-6,7-dioxacholestane derivatives 1. The final
形成在胆甾醇乙酸酯的反应和其它Δ的过程中对产品的结构5在含醇的溶剂-steroids用臭氧已经修订。参与溶剂的产物是氢过氧化物,5α-氢过氧-7α-烷氧基-5α-B-homo-6-氧杂类固醇3而不是先前要求保护的环状半缩醛,5α-羟基-7a-烷氧基-B-dihomo-6,7-二氧杂胆甾烷衍生物1.从选定的氢过氧化物3a,3c和3j的X射线晶体结构分析中获得了最后的证据。提出涉及氢过氧基和烷氧基的氢键负责这些氢过氧化物的稳定性,并且在醇对Criegee中间体12的亲核进攻中也起指导作用。