Chapter 7, Problem 57P

(a)

Interpretation Introduction

Interpretation:

The way by which given compound is synthesized from ethyne should be given.

Concept Introduction:

Lindlar catalyst: The catalyst is used for the hydrogenation of alkynes in a syn manner.  This means both hydrogen are added on the same side across the triple bond and the product obtained will be a cis product.

Sodium in liquid ammonia: The catalyst is used for the formation of trans alkenes from alkynes.  Because of its more reactivity towards triple bonds, the reaction will stop at the formation of alkenes.

$Pd/C$: Hydrogenation can done using this catalyst and converts alkenes to alkanes.  The addition will be a syn addition.

Erythro isomer: In a Fischer Projection formula, if identical substituents are on the same side, then the isomer can be called as erythro.

Threo isomer: In a Fischer projection formula, if identical substituents are on the different side, then the isomer can be called as threo.

Meso compound: It is a symmetric compound which has the plane of symmetry.  If there are two chirality centres and same set of four groups are attached on each chirality centre, then it can be called as meso compound.

(b)

Interpretation Introduction

Interpretation:

The way by which given compound is synthesized from ethyne should be given.

Concept Introduction:

Lindlar catalyst: The catalyst is used for the hydrogenation of alkynes in a syn manner.  This means both hydrogen are added on the same side across the triple bond and the product obtained will be a cis product.

Sodium in liquid ammonia: The catalyst is used for the formation of trans alkenes from alkynes.  Because of its more reactivity towards triple bonds, the reaction will stop at the formation of alkenes.

$Pd/C$: Hydrogenation can done using this catalyst and converts alkenes to alkanes.  The addition will be a syn addition.

Erythro isomer: In a Fischer Projection formula, if identical substituents are on the same side, then the isomer can be called as erythro.

Threo isomer: In a Fischer Projection formula, if identical substituents are on the different side, then the isomer can be called as threo.

Meso compound: It is a symmetric compound which has the plane of symmetry.  If there are two chirality centres and same set of four groups are attached on each chirality centre, then it can be called as meso compound.