2-Pyrrolidinones and 3-Pyrrolin-2-ones: A Study on the Chemical Reactivity of These Structural Moieties

Table 2

¹H NMR data of the isomers 4a and 4b.

Hydrogens	4a	4b
	𝛿 (Multiplicity, J/Hz)	𝛿 (Multiplicity, J/Hz)
N-H	6.55 (bs)	6.90 (bs)
C3-H	4.46 (dd, 2.4 and 7.3)	4.32 (dd, 4.9 and 7.5)
C4-H	2.76–2.50 (m)	2.78–2.50 (m)
	2.42–2.24 (m)	2.42–2.24 (m)
C5-H	3.50–3.24 (m)	3.65–3.48 (m)
		3.48–3.25 (m)