4-Methoxy-4-oxobutanoic acid, CH3OCO-CH2CH2-COOH, is treated in separate experiments with (X) B2H6 in THF followed by water, and (Y) excess LiAlH4 followed by acid work-up. The major organic products are

X = methyl 4-hydroxybutanoate; Y = butane-1,4-diol

X = 4-methoxy-4-oxobutanal; Y = methyl 4-hydroxybutanoate

X = butane-1,4-diol; Y = butane-1,4-diol

X = butane-1,4-diol; Y = methyl 4-hydroxybutanoate

X = methyl 4-hydroxybutanoate; Y = butane-1,4-diol

JEE Advanced levelSingle correct optionDifficulty 3 of 3co211

4-Methoxy-4-oxobutanoic acid, $CH X_{3} OCO - CH X_{2} CH X_{2} - COOH$ , is treated in separate experiments with (X) $B X_{2} H X_{6}$ in THF followed by water, and (Y) excess $LiAlH X_{4}$ followed by acid work-up. The major organic products are

Diborane reduces the carboxylic acid selectively and leaves the ester untouched, giving methyl 4-hydroxybutanoate.

LiAlH X_{4}

reduces both the acid and the ester, giving butane-1,4-diol (plus methanol).