Chapter 7, Problem 74PP

(a)

Interpretation Introduction

Interpretation:

Stereo selectivity of the given reaction should be explained under given basic condition.

Concept Introduction:

Elimination Reaction: It is just reverse reaction of addition where substituent from the given molecule is removed via $E1$ (the reaction depends only on the substrate involved in the reaction) or $E2$ (the reaction depends on both of the substituents in the reaction) mechanism.

E1 reaction is a unimolecular elimination reaction to produce alkene compounds in which carbocation is formed as an intermediate and it has stepwise mechanism.

E2 reaction is a bimolecular elimination reaction in which alkene compounds formed in a single step.

Elimination of compound in presence of bulky base leads to less substituted alkene, in presence of strong base (not bulky) leads to more substituted alkene.

Stereoisomers: These types of isomers that have same molecular formula and connectivity but differ in the way of atoms are oriented space. For example the difference between two stereoisomers lies only in the three dimensional arrangement of atoms.

Stereospecific reaction: reaction undergoes from a stereoisomer to a unique stereo isomeric product.

Newman projection: Newman projection of molecule is one type of representations for the alkanes, where the projection visualization from one carbon to another carbon. In this Newman projection, front carbon which represented with dot is called proximal and the back carbon which represented with circle is called distal.

  

From the angle of observer the front carbon is proximal and second carbon is distal.

In wedge-dash line representation wedge is coming out of the plane and dash is going behind the plane, the wedge line and the dash line of front carbon in Newman projection are pointing up and the wedge line and the dash line of back carbon in Newman projection are pointing down.

(b)

Interpretation Introduction

Interpretation:

Stereo selectivity of the given reaction should be explained under given basic condition.

Concept Introduction:

Elimination Reaction: It is just reverse reaction of addition where substituent from the given molecule is removed via $E1$ (the reaction depends only on the substrate involved in the reaction) or $E2$ (the reaction depends on both of the substituents in the reaction) mechanism.

E1 reaction is a unimolecular elimination reaction to produce alkene compounds in which carbocation is formed as an intermediate and it has stepwise mechanism.

E2 reaction is a bimolecular elimination reaction in which alkene compounds formed in a single step.

Elimination of compound in presence of bulky base leads to less substituted alkene, in presence of strong base (not bulky) leads to more substituted alkene.

Stereoisomers: These types of isomers that have same molecular formula and connectivity but differ in the way of atoms are oriented space. For example the difference between two stereoisomers lies only in the three dimensional arrangement of atoms.

Stereospecific reaction: reaction undergoes from a stereoisomer to a unique stereo isomeric product.

Newman projection: Newman projection of molecule is one type of representations for the alkanes, where the projection visualization from one carbon to another carbon. In this Newman projection, front carbon which represented with dot is called proximal and the back carbon which represented with circle is called distal.

From the angle of observer the front carbon is proximal and second carbon is distal.

In wedge-dash line representation wedge is coming out of the plane and dash is going behind the plane, the wedge line and the dash line of front carbon in Newman projection are pointing up and the wedge line and the dash line of back carbon in Newman projection are pointing down.