Aminosteroids were prepared and acylated with protected amino acids by means of the mixed anhydride or the active ester method. The tert-butyloxycarbonyl- (BOG) protecting group was eliminated by acidolysis, and the benzyloxycarbonyl- (Z) group by catalytic hydrogenation. 3 beta- and 6 beta-Glycylamidosteroids were prepared by indirect amination of chloroacetamido derivatives, formed by the Ritter reaction on the corresponding 3 alpha,5 alpha-cyclo and 5 alpha,6 alpha-epoxy steroids. Water-soluble double salts were produced from the compounds for pharmacological investigations. (C) 1996 by Elsevier Science Inc.
Conversion of the cholesterol sidechain to a 17-acetyl group by remote chlorination reactions
作者:Uday Maitra、Ronald Breslow
DOI:10.1016/s0040-4039(00)84722-x
日期:——
Two methods to convert cholesterol to pregnane derivatives are described. In one, templatedirectedchlorination of C-20 with an iodoaryl esterattached at the 6 β position was used to convert i-cholesterol to pregnenolone.