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13 C NMR study on linderones and lucidones
Author(s) -
Ng Soon,
Lee HiokHuang,
Bennett Graham J.
Publication year - 1990
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260280411
Subject(s) - chemistry , tautomer , intramolecular force , deuterium , deuterium nmr , chemical shift , coupling constant , nmr spectra database , carbon 13 nmr satellite , kinetic isotope effect , spectral line , nuclear magnetic resonance spectroscopy , carbon 13 nmr , proton nmr , nuclear overhauser effect , stereochemistry , crystallography , fluorine 19 nmr , particle physics , quantum mechanics , astronomy , physics
The 13 C NMR spectra of linderone (1), lucidone (2), methyllinderone (3), methyllucidone (4), demethyllinderone (7), dihydrolinderone (8) and 2‐(1‐hydroxyethylidene)‐4‐methylcyclopent‐4‐ene‐1,3‐dione (9) are reported. The 1 H chemical shift data for 1–4 are also reported. Geometric isomers exist in 4, while external tautomers exist in all the other compounds (except 3) through strong intramolecular hydrogen bonding. With the aid of deuterium isotope effects (in 1 and 2), C‐H coupling constants and nuclear Overhauser effects, the 13 C NMR spectra are assigned to the external tautomers and the geometric isomers.