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Which of the following statements is INCORRECT regarding NaBH4?

1. NaBH4 reduces aldehydes and ketones to alcohols
2. NaBH4 does not reduce carboxylic acids and esters under normal conditions
3. NaBH4 reduces acyl halides, aldehydes, and ketones but not carboxylic acids
4. NaBH4 is a milder reducing agent compared to LiAlH4

Correct answer: NaBH4 reduces acyl halides, aldehydes, and ketones but not carboxylic acids

Solution

NaBH4 (sodium borohydride) is a mild selective reducing agent. It reduces aldehydes and ketones to primary and secondary alcohols respectively. It does NOT reduce carboxylic acids, esters, amides, or acyl halides under normal conditions. This is in contrast to LiAlH4, which reduces all these functional groups. The statement that NaBH4 reduces acyl halides is incorrect — acyl halides are NOT reduced by NaBH4 under standard conditions.

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