REDUCTIVE CONVERSION OF CARBONYL-COMPOUNDS BY YEAST .2. IMPROVED CONDITIONS FOR THE PRODUCTION AND CHARACTERIZATION OF 1-ARYLPROPANE-1,2-DIOLS AND RELATED-COMPOUNDS

Improved conditions for the production and characterization of 1-arylp ropane-1,2-diols and related compounds were developed, Experimental co nditions providing highly enhanced activity of pyruvate decarboxylase in bakers' yeast in the presence of pyruvate, thiamine pyrophosphate, and magnesium(II) salt were applied to the preparation of (R)-1-hydrox y-1-phenyl-2-propanone from benzaldehyde, Subsequent reduction with ba kers' yeast efficiently afforded 1-phenyl-1,2-propanediol (35%), The c omposition of its stereoisomers was precisely determined, and the majo r (1R,2S)-isomer (89% of the total mixture) could be isolated by recry stallizing the corresponding benzoate. The analytical method for ident ifying the stereoisomeric composition was also effective for the deter mination of 5-phenyl-4-pentene-2,3-diol, the biotransformation product from cinnamaldehyde, the vinylogous substrate of benzaldehyde, Furthe rmore, the structural characterization of 1-(2-furyl)propane-1,2-diol, which was obtained from furfural (28%) by the action of brewers' yeas t Saccharomyces cerevisiae (carlsbergensis), is described, The major ( 1S,2S)-isomer could be isolated by recrystallizing the crude product.