Question

How many peaks are observed in the ¹HNMR signal for each proton shown in red in palau'amine, the complex chapter-opening molecule?

Short answer

Ha : doublet

Hb : doublet

Hc : singlet

Hd : doublet

Step-by-step solution

The (n+1) rule

The (n +1) rule is used to predict the multiplicity of¹HNMR peaks.

n represents the number of hydrogen atoms present on the carbon atoms adjacent to the carbon to which the desired hydrogen is connected.

Peaks observed in the 1HNMR spectrum of palau'amine

The number of peaks observed for the indicated hydrogen atoms is as follows:

Ha: 1 + 1 = 2(doublet).

Hb: 1 + 1 = 2 (doublet)

Hc: singlet (as it is connected to a nitrogen atom).

Hd : 1 + 1 = 2 (doublet)