3-Hydroxypyrroles and 1H-pyrrol-3(2H)-ones. Part 6. 1H and 13C n.m.r. spectra of 1-substituted, 1,2-disubstituted, and 1,2,2-trisubstituted 1H-pyrrol-3(2H)-ones

Abstract

¹ H and ¹³C n.m.r. parameters of the 1H-pyrrol-3(2H)-one system are discussed. Typical values for the 1-t-butyl derivative (2) are as follows: 2-position, δ_H 3.70, ⁴J_2.5 0.9 Hz; δ_c 54.19, ¹J_CH 141.2, and ³J_4–H[=³J_5–H] 5.2 Hz; 3-position, δ_C 199.76, ³J_5–H 10.2, ²J_4–Hca. 3, and ²J_2–Hca. 4.5 Hz; 4-position, δ_H 5.09, ³J_4.5 3.4 Hz; δ_C 99.13, ¹J_CH 176.5 and ²J_5–H 6.8 Hz; 5-positions, δ_H 7.93, ³J_4.5 3.4 and ⁴J 0.9 Hz; δ_C 162.58, ¹J_CH 173.0, ²J_4–H 8.5, and ³J_2–H 4.0 Hz The effects of substituents on these parameters are also considered.