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Eremophilane esters of Robinsonecio gerberifolius and their rearranged products. Study of the coupling constants 2 J H, H , 3 J H, H and 4 J H, H
Author(s) -
Arciniegas Amira,
PérezCastorena AnaL.,
Cuevas Gabriel,
del RíoPortilla Federico,
de Vivar Alfonso Romo
Publication year - 2006
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.1719
Subject(s) - chemistry , coupling constant , autoxidation , stereochemistry , sesquiterpene , peroxide , additive function , dept , nmr spectra database , computational chemistry , spectral line , organic chemistry , mathematical analysis , physics , mathematics , particle physics , astronomy
In the course of the basic hydrolysis of four eremophilane esters isolated from Robinsonecio gerberifolius , some rearrangements, eliminations, and additions occurred. Five compounds were obtained, three of them not previously described. Additionally, a new sesquiterpene was produced by autooxidation of compound 1. The 1 H and 13 C NMR spectra of these compounds were completely assigned by utilization of HMQC, HMBC, COSY, DEPT, and NOESY techniques. The long‐range coupling constants of the peroxide 10 are reported, and all its coupling constants 2 J H, H , 3 J H, H , and 4 J H, H are calculated at the B3LYP/6‐31G(d,p) level of theory. Their magnitude is explained in terms of electronic delocalization and the additivity of stereoelectronic effects. Copyright © 2005 John Wiley & Sons, Ltd.