Ethyl 4-acetylbenzoate, $CH X_{3} CO - C X_{6} H X_{4} - COOC X_{2} H X_{5}$ (para), is treated with (i) $NaBH X_{4}$ in methanol and, in a separate experiment, (ii) excess $LiAlH X_{4}$ in ether followed by $H X_{3} O X^{+}$ . The major products are respectively

Aethyl 4-(1-hydroxyethyl)benzoate; ethyl 4-ethylbenzoate
Bethyl 4-(1-hydroxyethyl)benzoate; 1-[4-(hydroxymethyl)phenyl]ethanol
Cethyl 4-ethylbenzoate; 4-ethylbenzyl alcohol
D1-[4-(hydroxymethyl)phenyl]ethanol; ethyl 4-(1-hydroxyethyl)benzoate

Answer: B

NaBH X_{4}

in methanol reduces the ketone but not the ester, giving the hydroxy ester.

LiAlH X_{4}

reduces both groups: the ketone to a secondary alcohol and the ester to the benzylic primary alcohol (ethanol is lost). The second product is therefore the diol 1-[4-(hydroxymethyl)phenyl]ethanol.

Practice Reduction, Oxidation and Hydrolysis in Organic Chemistry More on Catalytic hydrogenation and metal hydride reductions (LiAlH4, NaBH4, DIBAL)

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Ethyl 4-acetylbenzoate, CHX3​CO−CX6​HX4​−COOCX2​HX5​ (para), is treated with (i) NaBHX4​ in methanol and, in a separate experiment, (ii) excess LiAlHX4​ in ether followed by HX3​OX+. The major products are respectively

Answer: B

More questions on Catalytic hydrogenation and metal hydride reductions (LiAlH4, NaBH4, DIBAL)

Ethyl 4-acetylbenzoate, $CH X_{3} CO - C X_{6} H X_{4} - COOC X_{2} H X_{5}$ (para), is treated with (i) $NaBH X_{4}$ in methanol and, in a separate experiment, (ii) excess $LiAlH X_{4}$ in ether followed by $H X_{3} O X^{+}$ . The major products are respectively