Methylsteroids. VII. Factors Affecting the Hydrolysis of 7α- and 11β-Acetoxylanostanes

Abstract

Doubly bonded methylene groups have been introduced into 7α- and 11β-acetoxylanostanes and the rate of hydrolysis compared with compounds having a hydroxy or carbonyl group at the same position as the methylene group. It was found that methylene groups facilitate hydrolysis of the hindered acetoxy groups in the same way, but not to the same extent, as carbonyl groups. It is concluded that the facilitation in each case results from a conformational disturbance, but that there is some other factor involved in carbonyl facilitation. It was not possible to demonstrate a similar effect resulting from steric crowding of substituents.