Question

How many NMR signals would you expect for each compound?

a.

b.

c.

Short answer

a. 4

b. 5

c. 5

Step-by-step solution

NMR spectroscopy

The chemical shift of a proton is affected by the presence of an electronegative atom. The proton around the electronegative atom is deshielded, due to which it absorbs downfield.

 1H NMR signals in a, b and c

a.

The given compound has four types of protons, and it will give four signals, as shown below.

Structure of a

b.

The given compound has five types of protons, and it will give five signals, as shown below.

Structure of b

c.

The given compound has five types of protons, and it will give five signals, as shown below.

Structure of c