ISSN:
0749-1581
Keywords:
Long-range
;
13C—1H coupling constants
;
Long-range 13C—1H J-resolution spectroscopy
;
Chrysanthemic acid
;
Pyrethroid
;
2D NMR
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Two-dimensional long-range 13C—1H J-resolution spectroscopy (LRCJR) was used to measure three-bond 13C—1H coupling constants [3J(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 3J(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 3J(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 3J(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.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260310118
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