Question

If 3 hexanone is reacted with any bh4 followed by hydrolysis with d2o the product will be

Answer 1

NaBH4 is a source of hydride (H-) and the reaction begins with the addition of hydride to the carbonyl to the aldehyde (Step 1, arrows A and B).

Answer 2

NaBH4 reacts with water and alcohols, with evolution of hydrogen gas and formation of the borate salt, the reaction being especially fast at low pH. Nevertheless, an alcohol, often methanol or ethanol, is generally the solvent of choice for sodium borohydride reductions of ketones and aldehydes !