The major product formed in the following reaction sequence is iii. Ph₃P=CH₂, THF · ABC26OR0901
Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reagents, Reaction Mechanisms & Named Reactions – General · Exam: JAM 2005-2022 · Marks: 2 · Difficulty: Medium
The major product formed in the following reaction sequence is 
iii. $\mathrm{Ph_3P{=}CH_2}$, THF
iii. $\mathrm{Ph_3P{=}CH_2}$, THF(a)
(b)
(c)
(d)
Answer
Answer: B ✓ checked by 4AB · confidence high
Explanation
1,2-Addition of EtMgBr gives a tertiary allylic alcohol. CrO₃ causes oxidative 1,3-transposition (Babler–Dauben) to 3-ethylcyclohex-2-enone, and Wittig methylenation gives 1-ethyl-3-methylenecyclohexene (b).
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