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JEE Advanced levelSingle correct optionDifficulty 3 of 3o1095

What is the minimum number of moles of $LiAlH X_{4}$ required to reduce completely 1 mol of ethyl 4-oxopentanoate to the corresponding diol (assume all four Al-H bonds can deliver hydride and ignore other consumption)?

A0.50
B0.25
C0.75
D1.00

Answer: C

The ketone needs one hydride and the ester needs two hydrides (aldehyde stage and then alcohol), so 3 mol of

H X^{-}

are needed per mole of substrate. Each

LiAlH X_{4}

supplies up to 4, so

3/4 = 0.75

mol.

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