Formation of cyclic enol ethers from a labile biological precursor: an example of analytical artifacts

Three isomeric enol ethers are among those constituents apparently unique to mouse urine as identified by gas chromatographic analysis. These compounds appear to be artifacts arising from the cyclization and dehydration of 6-hydroxy-6-methyl-3-heptanone. Identification of the trimethylsilyl ether of 6-hydroxy-6-methyl-3-heptanone in the silylated ether extract of mouse urine indicates that the precursor keto alcohol is indeed present in the urine. Since similar heterocyclic compounds are often identified in urine samples analyzed by gas chromatography, formation of various analysis artifacts arising from analogous cyclization and dehydration reactions is likely.