Q10 · CSIR-NET Chemistry, June 2015
Paper: CSIR-NET June 2015 · Subject: Organic Chemistry · Chapter: General Organic Chemistry · Topic: General Organic Chemistry – General · Marks: 2 · Difficulty: Hard
The correct order of magnitude of 'A values' for the given substituents in cyclohexane derivatives is 
$X = CH_3, CN, Ph$
$X = CH_3, CN, Ph$(a)Ph $>$ CN $>$ Me
(b)$\mathrm{Me}>\mathrm{Ph}>\mathrm{CN}$
(c)CN $>$ Me $>$ Ph
(d)$\mathrm{Ph}>\mathrm{Me}>\mathrm{CN}$
Answer
Answer: D ✓ checked by 4AB · confidence high
Explanation
A values (kcal mol⁻¹): Ph 2.8 > Me 1.7 > CN 0.2 — the slim linear cyano group barely prefers equatorial.
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