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Three‐bond 13 C 1 H coupling constants for chrysanthemic acid and phenothrin metabolites: Detection by two‐dimensional long‐range 13 C 1 H J ‐resolution spectroscopy
Author(s) -
Ando Tetsu,
Koseki Nozomu,
Toia Robert F.,
Casida John E.
Publication year - 1993
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.1260310118
Subject(s) - chemistry , geminal , cyclopropane , stereochemistry , hydroxymethyl , coupling constant , spectroscopy , computational chemistry , ring (chemistry) , organic chemistry , physics , particle physics , quantum mechanics
Two‐dimensional long‐range 13 C 1 H J ‐resolution spectroscopy (LRCJR) was used to measure three‐bond 13 C 1 H coupling constants [ 3 J (C,H)] for trans ‐ and cis ‐chrysanthemic acid, methyl trans ‐pyrethrate and some microsomal metabolites of the trans ‐chrysanthemate biophenothrin. The carbon of the methyl cis ‐disposed to an attached proton shows a larger 3 J (C,H) value than does the trans ‐carbon for the dimethyl‐substituted cyclopropane and epoxide rings. The reverse situation applies for the analogous dimethyl vinyl grouping. The 3 J (C,H) values are not altered on conversion of one of the olefinic geminal methyl groups to a hydroxymethyl or methoxycarbonyl functionality, but increase on transformation to an aldehyde. These 3 J (C,H) values are in agreement previous results from long‐range CH COSY experiments, and provide a useful method for determining the stereochemistry of chrysanthemic acid derivatives.