Which of the following alkenes, on treatment with BH3.THF followed by H2O2/NaOH, give a mixture of two constitutionally isomeric alcohols in comparable amounts?

but-2-ene (either geometric isomer)

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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3o2052

Which of the following alkenes, on treatment with $BH X_{3} \cdot THF$ followed by $H X_{2} O X_{2} / NaOH$ , give a mixture of two constitutionally isomeric alcohols in comparable amounts?

A(E)-pent-2-ene
Bbut-2-ene (either geometric isomer)
Chex-2-ene
Dcyclopentene

Answer: A, C

When the two sp

^{2}

carbons are about equally substituted, boron can attach to either one. (E)-Pent-2-ene gives pentan-2-ol and pentan-3-ol; hex-2-ene gives hexan-2-ol and hexan-3-ol. But-2-ene gives only butan-2-ol and cyclopentene gives only cyclopentanol, because of symmetry.

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Which of the following alkenes, on treatment with BHX3​⋅THF followed by HX2​OX2​/NaOH, give a mixture of two constitutionally isomeric alcohols in comparable amounts?

Answer: A, C

More questions on Electrophilic addition to alkenes and Markovnikov rule

Which of the following alkenes, on treatment with $BH X_{3} \cdot THF$ followed by $H X_{2} O X_{2} / NaOH$ , give a mixture of two constitutionally isomeric alcohols in comparable amounts?