A Simplified Method for Synthesis of Tetrahydroiso-α-acid Standards for High-Performance Liquid Chromatography. Bruce A. Hay and John W. Homiski, Pfizer Central Research, Groton, CT 06340, and Matthew A. Priest, Pfizer Brewery Products Division, Milwaukee, WI 53212. J. Am. Soc. Brew. Chem. 49:0115, 1991.

A simplified method for synthesis of pure tetrahydroiso-α-acid homologs for use as high-performance liquid chromatography standards was developed. The synthesis involved converting phloroglucinol to β-acids followed by hydrogenation to 4-desoxytetrahydro-α-acids, oxidation to tetrahydro-α-acids, and isomerization to tetrahydroiso-α-acids. Carbon and proton nuclear magnetic resonance spectra of the standards showed that each consisted of a single isomer. The standards were assigned the cis configuration based on a comparison of the carbon nuclear magnetic resonance spectra with those of the isohumulones.

Keywords: Hops, High-performance liquid chromatography, Standards, Tetrahydroiso-α-acids, Synthesis