Alcaloïdes stéroïdiques CVIII : Elimination trans stéréosélective, en milieu alcalin, d'un oxaziranne stéroïdique, dérivé de la conanine

Abstract

Treatment of the steroïdal oxazirane 11, specifically monodeuteriated in the 18α position, with an aqueous ethanolic solution of potassium hydroxide, gives a reaction whose first step is a trans, E 2 type concerted elimination. Oxaziranes bearing an hydrogen on the carbon α to the nitrogen are known to undergo successively elimination and hydrolysis (formation of ammonia and carbonyl derivatives). The present work is a verification of the Emmons' hypothesis of the occurence of a concerted elimination mechanism.