1H and 13C dynamic NMR study of the E, Z isomers of vinylogous diamides. Effect of conjugation and electrostatic and steric repulsion on the C(O)N rotation barriers and low-temperature conformation

1H and 13C NMR studies on the conformati

1H and 13C NMR studies on the conformation of E,Z-diastereomers of N-desmethyl-N,O-diacetyl-α-metazocine (sp2-hybridized nitrogen derivatives of a benzomorphan narcotic analgesic)

✍ Robert Glaser; Michael A. Bernstein; Ayala Balan 📂 Article 📅 1991 🏛 John Wiley and Sons 🌐 English ⚖ 768 KB

## Abstract The ^1^H (300 MHz) and ^13^C (75.5 MHz) NMR spectra (CDCl~3~) of __N__‐desmethyl‐__N__,__O__‐diacetyl‐α‐metazocine showed two (__E__,__Z__)‐amide diastereomers (ratio ≈︁ 1 : 2, respectively). All four vicinal proton‐proton coupling constants in each NCH~2~CH~2~C moiety were readily meas