3-BOND C-13-H-1 COUPLING-CONSTANTS FOR CHRYSANTHEMIC ACID AND PHENOTHRIN METABOLITES - DETECTION BY 2-DIMENSIONAL LONG-RANGE C-13-H-1 J-RESOLUTION SPECTROSCOPY

Two-dimensional long-range C-13-H-1 J-resolution spectroscopy (LRCJR) was used to measure three-bond C-13-H-1 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(CH) 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.