Predict the major product 'P' in the following sequence of reactions - (i) HBr, benzoyl peroxide; (ii) KCN; (iii) Na(Hg)/ C₂H₅OH -> P (Major), starting from 1-methylcyclopentene 1. methylcyclopentane with CH₂NH₂ (see figure) 2. 1-methyl-1-( CH₂NH₂ )cyclopentane (see figure) 3. methylcyclopentane with CN (see figure) 4. 1-cyano-1-methylcyclopentane (see figure)

Answer: 1. methylcyclopentane with CH₂NH₂ (see figure) Key idea: HBr with peroxide adds anti-Markovnikov, KCN replaces Br by CN, and Na(Hg)/ C₂H₅OH reduces CN to CH₂NH₂ . Peroxide effect: Br goes to the less substituted alkene carbon (C-2) and H to C-1, giving 2-bromo-1-methylcyclopentane. KCN ( S_N2 ): 2-methylcyclopentanecarbonitrile, CN on the carbon next to the CH₃ carbon. Reduction: -CN→-CH₂NH₂ . Product: methyl and CH₂NH₂ on adjacent ring carbons, option (1). Options (2) and (4) have both groups on the same carbon, which needs Markovnikov addition; (3) and (4) show the unreduced cyano group (drawn as NC) and no amine.

Topic: Amines: nomenclature, classification, structure, preparation· Organic Compounds Containing Nitrogen

Predict the major product 'P' in the following sequence of reactions -(i) HBr, benzoyl peroxide; (ii) KCN; (iii) Na(Hg)/C_2H_5OH -> P (Major), starting from 1-methylcyclopentene

Predict the major product 'P' in the following sequence of reactions -

(i) HBr, benzoyl peroxide; (ii) KCN; (iii) Na(Hg)/\(\mathrm{C_2H_5OH}\) -> P (Major), starting from 1-methylcyclopentene

Reactant: cyclopentene ring with CH3 on a ring carbon; options are cyclopentane structures: (1) CH3 and CH2NH2 on adjacent ring carbons, (2) CH3 and CH2NH2 on the same carbon, (3) CH3 and CN on adjacent carbons, (4) CH3 and CN on same carbon

1. methylcyclopentane with \(\mathrm{CH_2NH_2}\) (see figure)

2. 1-methyl-1-(\(\mathrm{CH_2NH_2}\))cyclopentane (see figure)

3. methylcyclopentane with CN (see figure)

4. 1-cyano-1-methylcyclopentane (see figure)

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Answer: 1. methylcyclopentane with \(\mathrm{CH_2NH_2}\) (see figure)

Key idea: HBr with peroxide adds anti-Markovnikov, KCN replaces Br by CN, and Na(Hg)/\(\mathrm{C_2H_5OH}\) reduces CN to \(\mathrm{CH_2NH_2}\).

Peroxide effect: Br goes to the less substituted alkene carbon (C-2) and H to C-1, giving 2-bromo-1-methylcyclopentane.
KCN (\(S_N2\)): 2-methylcyclopentanecarbonitrile, CN on the carbon next to the \(\mathrm{CH_3}\) carbon.
Reduction: \(-\mathrm{CN}\to-\mathrm{CH_2NH_2}\).

Product: methyl and \(\mathrm{CH_2NH_2}\) on adjacent ring carbons, option (1). Options (2) and (4) have both groups on the same carbon, which needs Markovnikov addition; (3) and (4) show the unreduced cyano group (drawn as NC) and no amine.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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Predict the major product 'P' in the following sequence of reactions -(i) HBr, benzoyl peroxide; (ii) KCN; (iii) Na(Hg)/C_2H_5OH -> P (Major), starting from 1-methylcyclopentene

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