No abstract

With the aim of preparing steroids of the 19-hydroxypregnane series, 3p ,5,19trihydroxyetiocholanic acid (I) (1) and some of its esters were subjected to various chemical reactions.

As has been stated previously (2,3) it is intended to synthesize certain analogs of steroid hormones where the angular carbon atom between rings A and B is either missing (19-nor compounds) or is present in an oxygenated form, i.e. as a primary alcohol, aldehyde, or carboxyl group. In particular, compounds structurally derived from progesterone, 11-desoxycorticosterone, and 17-hydroxy-lldesoxycorticosterone (Reichstein's substance S) are of interest. A promising starting material appeared to be ethyl 3/3,5,19-trihydroxyetiocholanate (I) which in turn can be obtained by partial synthesis from strophanthidin (1, 2). The purpose of the present investigation was the conversion of I into further suitable intermediates towards this general aim.In an earlier publication (3) it was shown that, by means of N-bromoacetamide, I can be selectively oxidized to ethyl 3-keto-5,19-dihydroxyetiocholanate which under the influence of Girard's Reagent T is smoothly dehydrated to ethyl 3keto-19-hydroxy-A4-etiocholenate (IX). It has been found that the free 3/3,5,19trihydroxyetiocholanic acid (III), as obtained by saponification of I, can be subjected to the same reaction. Thus, when III was oxidized with N-bromoacetamide, followed by suitable treatment of the reaction product with Girard's Reagent T, a satisfactory yield of 3-keto-19-hydroxy-A4-etiocholenic acid (X) was obtained. The methyl ester (XI) and the known ethyl ester (IX) (3) were