Q27 · CSIR-NET Chemistry, June 2011
Paper: CSIR-NET June 2011 · Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reagents, Reaction Mechanisms & Named Reactions – General · Marks: 2 · Difficulty: Hard
Under review — part of this question (a structure or an option) is not clear in the source scan. 4AB is checking it against the original book; the answer shown may change.
The major compound X formed in the following reaction exhibited a strong absorption at $
u_{max} 1765,mathrm{cm^{-1}}$ in the IR spectrum. The structure of X is: 
(a)
(b)
(c)
(d)
Answer
Under review — not yet confirmed.
Answer: D
The source book printed no answer; this one was worked out and checked — see the explanation.
Explanation
PCC oxidises the primary alcohol to the aldehyde, which cyclises with the secondary OH to the lactol; PCC oxidises the lactol to the γ-lactone (ν 1765 cm⁻¹) (d).
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