Question

Which of the following cannot be reduced to ketone and aldehyde with NaBH₄​ and methanol?

(a) 2-methyl propanal

(b) 2-methyl propanone

(c) 2-methyl butanal

(d) 2-methyl butanone

Answer 1

2-methyl butanone cannot be reduced to a ketone or an aldehyde with NaBH₄ and methanol because it's already a ketone. Reduction with NaBH₄ generally applies to carbonyl-containing compounds, and 2-methyl butanone is not suitable for this reaction.

Step-by-step explanation:

The student asked about which compounds cannot be reduced to ketone and aldehyde with NaBH₄ and methanol. Considering the options provided, 2-methyl butanone is already a ketone and therefore cannot be reduced to a ketone because it is already in that functional group. Ketones and aldehydes can be reduced to alcohols using sodium borohydride; however, reducing a ketone to another ketone or an aldehyde does not apply here.

The process they are describing typically involves the reduction of esters, carboxylic acids, and other carbonyl-containing compounds to aldehydes or ketones, not the other way around. In summary, 2-methyl butanone cannot be reduced to a ketone or an aldehyde with NaBH₄ because it is already a ketone. Other compounds like 2-bromobutane and 2-chloro-3-fluoro-4-methylheptane can typically be reduced to alcohols because they contain halogen groups that can be replaced.