Grignard reagents do not give carbonyl compounds with :

$CH_2=CH-CO-OCH_3$ (methyl acrylate,bp $81^\circ C$) + $CH_3-CH_2-CH_2-CH_2-OH$ (n-butyl alcohol,bp $117^\circ C$) $\xrightarrow{TsOH, \Delta} (A)$ (bp $145^\circ C$) + $CH_3OH$ (bp $65^\circ C$). Product $(A)$ of the above reaction is:

Which of the following is the most reactive compound toward a nucleophile?

In the following sequence of reactions,$CH_3-Br$ $\xrightarrow{KCN} A$ $\xrightarrow{H_3O^{+}} B$ $\xrightarrow[ether]{LiAlH_4} C$,the end product $(C)$ is:

The reaction of $RCOOH$ with $R'OH$ takes place in the presence of $H_2SO_4$ to form an ester. The intermediate in the reaction is:

Which of the following has the most acidic proton?