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Three-bond 13C1H coupling constants for chrysanthemic acid and phenothrin metabolites: Detection by two-dimensional long-range 13C1H J-resolution spectroscopy

✍ Scribed by Tetsu Ando; Nozomu Koseki; Robert F. Toia; John E. Casida


Publisher
John Wiley and Sons
Year
1993
Tongue
English
Weight
298 KB
Volume
31
Category
Article
ISSN
0749-1581

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✦ Synopsis


Abstract

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 CH COSY experiments, and provide a useful method for determining the stereochemistry of chrysanthemic acid derivatives.