98IDENTIFICATION OF 2 ISOMERS OF 4,5-DIHYDROXYHEXANOIC ACID GAMMA LACTONE IN CALIFORNIAN AND SPANISH FLOR SHERRIES

Two major components of the aroma extracts of one Californian and two Spanish Flor Sherries are identified as (–) 4R :5R or 4S:5S 4,5-dihydroxyhexanoic acid gamma lactone and (+) 4R:5S or 4S:5R 4,5-dihydroxyhexanoic acid gamma lactone; diastereomeric forms of 5-(1-hydroxyethyl)dihydro-2-(3H) furanone. Identifications were accomplished from the IR, MS, and NMR spectra of the sherry lactones and those of the known lactones synthesized from trans-4-hexenoic acid. Optical activity in the sherry lactones strongly indicates their production by enzyme mediated routes. The possibility that these lactones may be produced during the period of film growth of Saccharomyces beticus on the surface of the sherry is discussed. © 1969, American Chemical Society. All rights reserved.