Question

Reaction of ethyl formate with an excess of \[C{H_3}MgI\] followed by hydrolysis gives:
A. N-propyl alcohol
B. Isopropyl alcohol
C. Acetaldehyde
D. Acetone

Answer 1

Hint: Ethyl formate is an ester compound with chemical formula \[HCOO{C_2}{H_5}\]. Hydrolysis is a reaction which involves the addition of water.

Complete Step by Step Solution:
Ethyl formate is an ester compound produced by the reaction of alcohol and formic acid.
A Grignard reagent is a chemical compound with a general formula of \[RMgX\]. Here, R is the alkyl group and X is the halide group. It is an organomagnesium compound. The grignard reagent is formed by the reaction of aryl or alkyl halide with magnesium.
When Grignard reagent reacts with ethyl formate an intermediate product is formed which on hydrolysis leads to isopropyl alcohol.

First, the negative charge of the methyl group of Grignard reagent attacks the central carbon of ethyl formate and the ethyl group is removed, again the negative charge methyl group attack the carbon and an intermediate compound magnesium iodide propan-2-olate. The intermediate compound then undergoes hydrolysis which means the addition of a water molecule which results in the formation of the main product i.e, Isopropyl alcohol.

The reaction of ethyl formate with an excess of \[C{H_3}MgI\] followed by hydrolysis gives Isopropyl alcohol. Therefore, option B is correct.
The reaction mechanism is shown below.

Image: Formation of Isopropyl alcohol

Note: It should be noted that the ester compound needs two equivalent of a Grignard reagent to produce tertiary alcohol. On the other hand aldehyde and ketone requires one equivalent of Grignard reagent to form secondary alcohol and tertiary alcohol respectively.