JEE Main · 2020 · 04 Sep 2020 · Shift 2 · Hydrocarbons

The major product

[R]

in the following sequence of reactions is:

(A)(see structure)
(B)(see structure)
(C)(see structure)
(D)(see structure)
✓ Correct

Answer: (D)

Solution

The sequence begins with an alkyne, which on treatment with

HgS O_{4} / H_{2} S O_{4}

undergoes Markovnikov hydration to a ketone, and this is then reduced by

NaB H_{4}

to the corresponding secondary alcohol. Heating the alcohol with concentrated

H_{2} S O_{4}

brings about dehydration, and following Saytzeff's rule the water is lost so as to give the more substituted, more stable alkene, which is the major product

[R]

JEE Main · 2020 · 04 Sep 2020 · Shift 2 · Single correct option

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