The reagent(s) used in hydroboration oxidation of propene are
(A) \( B_2H_6 \)
(B) \( H_2O \)
(C) \( H_2O_2 \)
(D) \( OH^- \)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A), (B), (C) and (D)
Hydroboration–oxidation converts an alkene into an alcohol. Diborane adds across the double bond to give a trialkylborane, which is then oxidised by hydrogen peroxide in aqueous sodium hydroxide. The net result is addition of water against Markovnikov’s rule, so propene gives propan-1-ol:
\( \displaystyle \ce{6CH3-CH=CH2 + B2H6 -> 2(CH3-CH2-CH2)3B} \)
\( \displaystyle \ce{(CH3-CH2-CH2)3B} \xrightarrow{\ce{3H2O2},\ \ce{OH-}} \ce{3CH3-CH2-CH2-OH + B(OH)3} \)
(A) \( \ce{B2H6} \) — Correct. Diborane is the hydroborating reagent.
(B) \( \ce{H2O} \) — Correct. The oxidation is carried out in aqueous solution; water is part of the reagent system written for the oxidation step.
(C) \( \ce{H2O2} \) — Correct. Hydrogen peroxide oxidises the C–B bonds to C–OH.
(D) \( \ce{OH-} \) — Correct. The oxidation needs alkaline conditions (aqueous NaOH).
NCERT (2026-27 edition):
By Hydroboration–Oxidation
