Chapter 8, Problem 68PP

(a)

Interpretation Introduction

Interpretation:

A suitable reagent should be predicted for the given transformations.

Concept introduction:

Elimination reaction: In this reaction, two substituents are removed from the substrate to give the product in presence of base.

Anti-Markovnikov’s rule: unsymmetrical alkene reacts with hydrogen halide, halide ions goes to the less substitution position of carbon-carbon double bond which provides alkyl halides.

(b)

Interpretation Introduction

Interpretation:

A suitable reagent should be predicted for the given transformations.

Concept introduction:

Hydrobromination:

A hydrobromination reaction is one of the electrophilic additions to alkenes to yield the corresponding bromo alkanes. In this reaction the bromine atom adds to the double bond carbon which is having lesser number of hydrogen or more substituted carbon (Markovnikov's rule).

(c)

Interpretation Introduction

Interpretation:

A suitable reagent should be predicted for the given transformations.

Concept introduction:

Osmium tetra oxide:

Cis-alkene undergoes oxidation using osmium tetra oxide followed by hydrogen peroxide hydrolysis which furnish cis 1,2 diol.

  

(d)

Interpretation Introduction

Interpretation:

A suitable reagent should be predicted for the given transformations.

Concept introduction:

Elimination reaction: In this reaction, two substituents are removed from the substrate to give the product in presence of base.

Anti-dihydroxylation: It is a process of adding two –OH groups from different planes to the alkene. Alkenes are treated with peroxy acids followed by aqueous acids and gives anti-dihydroxylation products.

Syn-dihydroxylation: It is a process of adding two –OH groups from the same plane to the alkene. Potassium per manganite and osmium tetroxide etc, are used as reagents.