Identify products A and B from the given \({}^{\bf{1}}{\bf{H}}\) NMR data.

(A) Treatment of \({\bf{C}}{{\bf{H}}_{\bf{2}}}{\bf{ = CHCOC}}{{\bf{H}}_{\bf{3}}}\) with one equivalent of HCl forms compound A. A exhibits the following absorptions in its \({}^{\bf{1}}{\bf{H}}\)NMR spectrum: 2.2 (singlet, 3 H), 3.05 (triplet, 2 H), and 3.6 (triplet, 2H) ppm. What is the structure of A?

(B) Treatment of acetone \(\left( {{{\left( {{\bf{C}}{{\bf{H}}_{\bf{3}}}} \right)}_{\bf{2}}}{\bf{C = O}}} \right(\)with dilute aqueous base forms B. Compound B exhibits four singlets in its \({}^{\bf{1}}{\bf{H}}\) NMR spectrum at 1.3 (6 H), 2.2 (3 H), 2.5 (2 H), and 3.8 (1 H) ppm. What is the structure of B?

The number of signals in\({}^{\bf{1}}{\bf{H}}\)NMR spectrum of a compound depends on the chemical environment of the protons (hydrogen atoms) present in it.

The protons that share the same chemical environment resonate at the same frequency and hence give only a single signal.

The reaction of \({\rm{C}}{{\rm{H}}_{\rm{2}}}{\rm{ = CHCOC}}{{\rm{H}}_{\rm{3}}}\) HCl is provided below.

Reaction of \({\rm{C}}{{\rm{H}}_{\rm{2}}}{\rm{ = CHCOC}}{{\rm{H}}_{\rm{3}}}\) with HCl

The NMR signals given by the hydrogen atoms present in the compound is as follows:

NMR signals are shown by the protons of compound A

The signals are by following per under the spectral data of compound A.

The reaction of acetone with a dilute aqueous base is represented below.

Reaction of acetone with a base

The figure given below represents the hydrogen atoms present in compound B along with their chemical shift and splitting pattern.

NMR signals are shown by the protons of compound B

The NMR shifts shown by the hydrogen atoms of compound B are by following per under the spectral data provided.