Untersuchungen zur Regioselektivität von Wittig‐Horner‐ und Reformatsky‐Reaktionen an ausgewählten 3,17‐Dioxosteroiden

Abstract

Investigations on Regioselectivity of Wittig‐Horner and Reformatsky‐Reactions on Selected 3,17‐Dioxo SteroidsThe Reformatsky synthesis and the Wittig‐Horner olefination of 3,17‐dioxo steroids like androsta‐1,4‐diene‐3,17‐dione (ADD) 1 and androst‐4‐ene‐3,17‐dione (AD) 2 is described. There are differences in the regioselective introduction of identical substructures with these two methods resulting from different nucleophilicity and stereoelectronical relations of these two reagents. In Reformatsky synthesis the oxo group in 3‐position predominantly reacts, whereas in the Wittig‐Horner olefination (in the case of 1) the reaction occurs mainly in the 17‐position.The structures of all new compounds has been confirmed by spectroscopical data.