Chapter 23, Problem 71GQ

(a)

Interpretation Introduction

Interpretation:

The reactions is to be written for the reaction of $\text{cis-2-butene}$ with ${\text{H}}_{\text{2}}\text{O}$ reagents.

Concept Introduction:

Hydration:

When alkene is undergoes hydration with water in the presence of sulfuric acid which yields the alcohol. In this reaction, the water molecule will behave like a hydrogen halide to the alkene which gives the addition product this reaction is known as a hydration reaction.

  

Alkene is reaction with water in the presence of sulfuric acid, first step is proton (${\text{H}}^{\text{+}}$) addition to the double bond which forms carbocation (more stable carbocation) followed by addition of hydroxide ion (${}^{\text{-}}\text{OH}$) yields alcohol as a product. The stability of carbocation is given below, Tertiary carbocation is more stable than the secondary, secondary carbocation is more stable than primary.

  

In hydration reaction, sulfuric acid is act as a proton donor, which is the driving force of the reaction. Hydration reaction will not go without acid (sulfuric acid).

(b)

Interpretation Introduction

Interpretation:

The reactions is to be written for the reaction of $\text{cis-2-butene}$ with $\text{HBr}$ reagents.

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).

(b)

Interpretation Introduction

Interpretation:

The reaction is to be written for the reaction of $\text{cis-2-butene}$ with ${\text{Cl}}_{\text{2}}$ reagents.

Concept Introduction:

An alkene undergo halogenation reaction when it is treated with halogens. The addition of two halogen atoms takes place on the carbon-carbon double bond. The product formed is called as disubstituted haloalkanes.