Chapter 8, Problem 50P

Interpretation Introduction

Interpretation:

The retrosynthesis analysis and the actual synthesis are to be written for the preparation of each target molecule from the given starting molecule.

Concept introduction:

>

The retrosynthesis is a reaction that involves organic synthesis by converting the target molecule to starting materials through the formation of one or more intermediate.

>

on acid catalyzed dehydration, an alcohol gives the corresponding more substituted alkene as the major product.

>

The alkene, on reaction with halogen in water, undergoes addition of halogen and hydroxyl group across the double bond in a way that the halogen atom is bonded to the less substituted double bonded carbon atom and hydroxyl group is bonded to the more substituted double bonded carbon atom.

>

Alkenes, on halogenations, undergo addition of a molecule of halogen across the double bond and form corresponding dihaloalkane.

>

Alkenes react with hydrogen halide and yield haloalkane.

>

Alkenes, on hydration, form more substituted alcohol.

>

Alkenes, on hydroboration-oxidation, form less substituted alcohol.

>

Alkenes, in presence of peroxy acid, undergo epoxidation.

>

In presence of a strong base, alkyl halide undergoes elimination reaction and forms alkene.

Answer to Problem 50P

Solution:

The retrosynthetic analysis and the actual synthesis for the preparation of each target molecule from the given starting compound are as follows:

a) $\text{1-Propanol}$ from $\text{2-propanol}$

Retrosynthesis:

Synthesis:

b) $\text{1,2-Dibromopropane}$ from $\text{2-bromopropane}$

Retrosynthesis:

Synthesis:

c) $\text{1-Bromo-2-propanol}$ from $\text{2-propanol}$

Retrosynthesis:

Synthesis:

d) $\text{1-Bromo-2-methyl-2-propanol}$ from $\text{tert-butyl bromide}$

Retrosynthesis:

Synthesis:

e) $\text{1,2-Epoxypropane}$ from $\text{2-propanol}$

Retrosynthesis:

Synthesis:

f) $\text{tert-Butyl alcohol}$ from $\text{isobutyl alcohol}$

Retrosynthesis:

Synthesis:

g) $\text{ tert-Butyl iodide}$ from $\text{isobutyl iodide}$

Retrosynthesis:

Synthesis:

h) $\text{trans-2-Chlorocyclohexanol}$ from $\text{cyclohexyl chloride}$

Retrosynthesis:

Synthesis:

Explanation of Solution

a) $\text{1-Propanol}$ from $\text{2-propanol}$

Retrosynthetic analysis for the target molecule $\text{1-Propanol}$ and starting molecule $\text{2-propanol}$ is as follows:

The actual synthetic route for the above retrosynthesis is as follows:

b) $\text{1,2-Dibromopropane}$ from $\text{2-Bromopropane}$

Retrosynthetic analysis for the target molecule $\text{1,2-Dibromopropane}$ and starting molecule $\text{2-bromopropane}$ is as follows:

The actual synthetic route for the above retrosynthesis is as follows:

c) $\text{1-Bromo-2-propanol}$ from $\text{2-propanol}$

Retrosynthetic analysis for the target molecule $\text{1-Bromo-2-propanol}$ and starting molecule $\text{2-propanol}$ is as follows:

The actual synthetic route for the above retrosynthesis is as follows:

d) $\text{1-Bromo-2-methyl-2-propanol}$ from $\text{tert-butyl bromide}$

Retrosynthetic analysis for the target molecule $\text{1-Bromo-2-methyl-2-propanol}$ and starting molecule $\text{tert-butyl bromide}$ is as follows:

The actual synthetic route for the above retrosynthesis is as follows:

e) $\text{1,2-Epoxypropane}$ from $\text{2-propanol}$

Retrosynthetic analysis for the target molecule $\text{1,2-Epoxypropane}$ and starting molecule $\text{2-propanol}$ is as follows:

The actual synthetic route for the above retrosynthesis is as follows:

f) $\text{tert-Butyl alcohol}$ from $\text{isobutyl alcohol}$

Retrosynthetic analysis for the target molecule $\text{tert-Butyl alcohol}$ and starting molecule $\text{isobutyl alcohol}$ is as follows:

The actual synthetic route for the above retrosynthesis is as follows:

g) $\text{ tert-Butyl iodide}$ from $\text{isobutyl iodide}$

Retrosynthetic analysis for the target molecule $\text{ tert-Butyl iodide}$ and starting molecule $\text{isobutyl iodide}$ is as follows:

The actual synthetic route for the above retrosynthesis is as follows:

h) $\text{trans-2-Chlorocyclohexanol}$ from $\text{cyclohexyl chloride}$

Retrosynthetic analysis for the target molecule $\text{trans-2-Chlorocyclohexanol}$ and starting molecule $\text{cyclohexyl chloride}$ is as follows:

The actual synthetic route for the above retrosynthesis is as follows:

Therefore, the retrosynthesis and synthesis reactions for the given compounds were proposed.