Question

Question: Devise a synthesis of each compound from cyclopentane and any other required organic or inorganic reagents.

a.

b.

c.

d.

e.

Short answer

Answer

a.

b.

c.

d.

e.

Step-by-step solution

Specific reagents for reaction

• Reagent NBS/ROOR: selective bromination of allylic C-H

• Reagent KOC (CH₃)₃ : elimination of proton to form an alkene.

• Reagent mCPBA: formation of an achiral epoxide

 Step 2: Synthesis using specific reagents with compounds a and b

(a) Cyclopentane is treated with chlorine in the presence of light or heat to form chloro cyclopentane which then reacts with KOC(CH₃)₃ that forms cyclopentene. It further reacts with acid and water to produce cyclopentanol.

Synthesis of cyclo-pentanol

(b) Cyclopentane is treated with chlorine in the presence of light or heat to form chloro cyclopentane which then reacts with KOC(CH₃)₃ forming cyclopentene.

Cyclopentene reacts with mCPBA to give 1,2-epoxycyclopentane.

Synthesis of cyclopentene oxide

Synthesis using specific reagents with compounds c, d, and e

(C) Cyclopentane is treated with chlorine in the presence of light or heat to form chloro cyclopentane which then reacts with KOC(CH₃)₃ forming cyclopentene.

When cyclopentene is treated with NBS, it forms 3-bromocyclopent-1-ene. The latter, on treatment with bromine, gives 1,2,3-tribromocyclopentane

Synthesis of 1,2,3-tribromocyclopentane

(d) Cyclopentane is treated with chlorine in the presence of light or heat to form chloro cyclopentane which then reacts with KOC(CH₃)₃ forming cyclopentene.

When cyclopentene is treated with NBS, it forms 3-bromocyclopent-1-ene.

3-Bromocyclopent-1-ene reacts with the hydroxide to form cyclopent-2-enol.

Synthesis of 2-cyclopentenol

(e) Cyclopentane is treated with chlorine in the presence of light or heat to form chloro cyclopentane when then reacts with KOC(CH₃)₃ forming cyclopentene.

When cyclopentene is treated with bromine, it forms 1,2-dichloro cyclopentane. It further reacts with potassium cyanide to form chlorocyclopentancarbonitrile.

Chlorocyclopentancarbonitrile is treated with potassium hydroxide to form 2-hydroxycyclopentane carbonitrile.

Synthesis of 2-hydroxycyclopentane carbonitrile