Synthetic investigation on sterioids A & B

Abstract

The thesis entitled “Synthetic Investigations on Steroids” consists of two sections, A and B. Section A, dealing with the Investigations on a new route to oestrone, is subdivided into two chapters. In Chapter 1, following a brief account of the scope and objective of our investigations, an up to date review of the partial and total syntheses of oestrone is presented. Chapter 2 deals with the investigations carried out by us, and initially the synthesis of the bicyclic intermediate, viz. methyl 7'-(1 keto 6 methoxy 2 tetralidene) butyrate, is described. Earlier attempts to synthesise this bicyclic intermediate with a view to converting it into oestrone have been reported to be unsuccessful. Michael addition of methylacetoacetonitrile to the aforementioned bicyclic intermediate furnished two isomeric tricyclic unsaturated keto cyano esters possessing the required side chains at C 17 and suitable for building up the ring D. The stereochemistry of these isomeric tricyclic unsaturated keto cyano esters could not be definitely ascertained at this stage. The probable stereochemistry of their hydrogenation products and in turn of the parent unsaturated ketones has been discussed. Finally, our efforts to obtain homomarranolic ester from these tricyclic compounds resulted in the synthesis of -(2 methyl 2 amide 7 methoxy 1,2,3,4,4a,9,10,10a octahydrophenanthryl) propionic acid.

Section B deals with the synthesis of D homo 18,19 bisnor 17 hydroxy 7 androstene 6 one by a convergent scheme. After a brief survey of the various investigations carried out earlier on these lines, the synthesis of trans 1 hydroxy 5 decalone and its condensation with 1 acetyl (and ) cyclohexene resulting in the obtaining of D homo 18,19 bisnor 17 hydroxy 7 androstene 6 one as its 2,4 dinitrophenylhydrazone has been described.