Stereospecific reductions of 2-en-1-ols catalyzed by Clostridium kluyveri.

With ethanol as electron donor, resting cells of Clostridium kluyveri reduced (E)-2-methyl-2-buten-1-ol, (E)-3-methyl-2-penten-1-ol and (E)-2-methyl-3-phenyl-2-propen-1-ol to (R)-2-methyl-1-butanol, (R)-3-methyl-1-1-pentanol and (R)-2-methyl-3-phenyl-1-propanol, respectively. Within the experimental errors of ORD measurements the products were optically pure. That means that only one of the two possible trans additions to the carbon-carbon double bond of these derivatives of allyl alcohol took place. The reduction of (E)-2-methyl-3-phenyl-2-propen-1-ol was carried out in 2H2O buffer. Assuming tha all 3 substrates bind in an identical manner to the enzyme, the product should be (2R,3S)-2-methyl-3-phenyl-[2,3-2H2]-1-propanol. The optimal pH and ethanol concentration for the reduction have been determined. Under an atmosphere of hydrogen the reduction of the unsaturated alcohols proceeded incompletely and slower than in the presence of ethanol under an atmosphere of nitrogen.