Chapter 29, Problem 40P

Interpretation Introduction

(a)

Interpretation: The three dimensional structure for the given steroid is to be drawn.

Concept introduction: In ball-and-stick model, each colored ball represents a specific atom and each stick represents a bond.

Interpretation Introduction

(b)

Interpretation: The structure of stereoisomer formed by the reduction of ketone group with ${\text{H}}_{\text{2}}$, $\text{Pd}-\text{C}$ is to be predicted and the reason why only one stereoisomer is formed is to be stated.

Concept introduction: Ring-flipping converts equatorial bonds into axial bonds and axial bonds into equatorial bonds. The reduction of ketone into alcohol can be done by using reagent ${\text{H}}_{\text{2}}$ in the presence of palladium.