| abstract |
(3R,4S)-4-hydroxytetrahydrothiopyran-3-carboxylic esters, (2R,3S)-2-methyl-3-hydroxypentanoic acid and lower alkanol esters thereof, (3R,4R)-3-hydroxytetrahydrothiophene-4-carboxylic esters, (2R,3S)-2-methyl-3-hydroxybutyric acid and lower alkanol esters thereof, (3R,4R)-methyl 3-hydroxytetrahydrothiophene-4-carboxylate, (S)-3-hydroxypentanoic acid and lower alkanol esters thereof and processes for the preparation of these compounds by reaction of appropriate tetrahydrothiopyran- or tetrahydrothiopheneketocarboxylic esters by means of fermenting yeast and, if desired, desulphurisation, preferably by means of Raney nickel. |