Question

The compound of molecular formula $C_5{H}_{10}O\left(A\right)$ reacts with Tollen's reagent to give silver mirror but does not undergo aldol condensation. The compound $A$ is:

• A. $3-$pentanone
• B. $2,2-$dimethylpropanal
• C. $3-$hydroxy$-2-$pentene
• D. $3-$methylbutanal
• E. $3-$methyl$-2-$butanone

Answer 1

The correct option is B $2,2-$dimethylpropanal
Positive Tollen's test means its an aldehyde but negative aldol condensation means its an aldehyde with no $\alpha -H$. Therefore from the given options it should be option B. As others have $\alpha -H$ marked as $\ast$.