Chapter 31, Problem 31.35P

Interpretation Introduction

(a)

Interpretation: The skeletal structure of the anabolic steroid methenolone from the given description is to be drawn.

Concept introduction: Steroids are composed of tetracyclic lipids. They have structure containing three six membered ring and one five membered ring. Some of the steroids are biologically active.

Interpretation Introduction

(b)

Interpretation: The skeletal structure of the anabolic steroid methenolone from the given description about the configurations at the stereogenic centers is to be drawn.

Concept introduction: Steroids are composed of tetracyclic lipids. They have structure containing three six membered ring and one five membered ring. Some of the steroids are biologically active.

The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Interpretation Introduction

(c)

Interpretation: The structure of Primobolan, the product formed on the treatment of methenolone with ${\text{CH}}_{\text{3}}{\left({\text{CH}}_{\text{2}}\right)}_5\text{COCl}$ and pyridine is to be drawn.

Concept introduction: In the presence of base, the hydroxyl group loses its proton to form alkoxide. The alkoxide attacks on the carbonyl carbon of acyl chloride or acylic anhydride to leading to the formation of acyl group and removal of chloride. This process is known as acylation.