Answer the question on basis of passage given below:

A ketone [A] which undergoes haloform reaction gives compound [B] on reduction. Compound [B] on heating with sulphuric acid gives compound [C] which forms monozonide [D]. The compound [D] on hydrolysis in the presence of zinc dust gives compound [E]. Compound [E] on oxidation gives \(C_2H_4O_2\)[F]

Compound [E] in presence of dil. NaOH gives:

But-2-enal

The correct answer is option 1. But-2-enal.

From the given data in the passage the various reactions and be depicted as:

The compound E is Acetaldehyde (or ethanal). Ethanal reacts with dil. NaOH to form \(\beta \)-hydroxy butyraldehyde. The product is known as aldol and this is the example of the aldol condensation reaction. It is given by ketones or aldehydes having an \(\alpha \) hydrogen atom. Aldehyde and alcohol are represented by “Aldol”. When an aldehyde reacts with carbon at the α (alpha) site to the carbonyl of another molecule under basic or acidic conditions to obtain beta-hydroxy aldehyde.

Aldol condensation is an organic reaction in which enolate ion reacts with a carbonyl compound to form β− hydroxy aldehyde. It is followed by dehydration to give a conjugated enone and it plays a vital role in organic synthesis. It is creating a path to form carbon-carbon bonds. The reaction is: