Studies on isometheptene metabolism. Identification and stereochemistry of a major metabolite isolated from rat urine.

By gas chromatography-mass spectrometry of both underivatized samples and N-acetates, the major urinary metabolite of the antispasmodic drug (+/-)-isometheptene in the rat was identified as trans-2-methyl-6-methylamino-2-hepten-1-ol. The structure and stereochemistry of the metabolites was confirmed by comparing the properties of its N-acetate with those of an authentic sample of the N-acetate of trans-2-methyl-6-methylamino-2-hepten-1-ol which was obtained by a stereospecific trans-allylic hydroxylation of isometheptene acetate with selenium dioxide in ethanol. cis-2-Methyl-6-methylamino-2-hepten-1-ol was identified as a minor urinary metabolite of isometheptene in the rat.