13C NMR studies of heterocyclic naphtho- and anthraquinones. Deshielding effect on the carbonyl carbon with methyl substitution.
13C chemical shift assignment of several methyl substituted heterocyclic naphtho- and anthraquinones, including dihydronaphthofuranquinones, azaanthraquinones, benzopyrroloquinolinediones and benzothiophenoquinolinediones, are described. A deshielding effect due to a methyl group was observed over the neighbouring carbonyl carbon, in every case studied. 13C assignments were based on 2D experiments.
Salas
Cristian
C
Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Santiago22, Chile.
Armstrong
Veronica
V
López
Claudio
C
Tapia
Ricardo A
RA
D000880:Anthraquinones / Q000138:chemical synthesis / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002247:Carbon Isotopes; D009682:Magnetic Resonance Spectroscopy; D009285:Naphthoquinones / Q000138:chemical synthesis / Q000737:chemistry*
D000880:Anthraquinones; D002247:Carbon Isotopes; D009285:Naphthoquinones; D002244:Carbon