Enzymes in organic synthesis. 32. Stereospecific horse liver alcohol dehydrogenase-catalyzed oxidations of exo- and endo-oxabicyclic meso diols

1984 ◽  
Vol 62 (11) ◽  
pp. 2578-2582 ◽  
Author(s):  
J. Bryan Jones ◽  
Christopher J. Francis
Keyword(s):  
Alcohol Dehydrogenase ◽  
Organic Synthesis ◽  
Horse Liver Alcohol Dehydrogenase ◽  
Preparative Scale ◽  
Enantiomerically Pure ◽  
Liver Alcohol Dehydrogenase ◽  
Horse Liver ◽  
One Step ◽  
Catalyzed Oxidation ◽  
Enzymes In Organic Synthesis

Preparative-scale horse liver alcohol dehydrogenase-catalyzed oxidation of mesoexo- and endo-7-oxabicyclo[2.2.1]heptane diols provides a direct one-step route to enantiomerically pure chiral γ-lactones of the oxabicyclic series.

Enzymes in organic synthesis. 23. Effects of organic solvents on horse liver alcohol dehydrogenase-catalyzed oxidation

1982 ◽  
Vol 60 (8) ◽  
pp. 1030-1033 ◽  
Author(s):  
J. Bryan Jones ◽  
Harold M. Schwartz
Keyword(s):  
Alcohol Dehydrogenase ◽  
Organic Synthesis ◽  
Organic Solvents ◽  
Butyl Alcohol ◽  
Horse Liver Alcohol Dehydrogenase ◽  
Liver Alcohol Dehydrogenase ◽  
Tert Butyl Alcohol ◽  
Horse Liver ◽  
Catalyzed Oxidation ◽  
Enzymes In Organic Synthesis

The effects have been evaluated of up to 50% (v/v) of methanol, tert-butyl alcohol, dimethylsulfoxide, sulfolane, acetonitrile, dimethylformamide, N-methyl-2-pyrrolidone, hexamethylphosphoramide, acetone, 2-butanone, tetrahydrofuran, dimethoxyethane, diglyme, and dioxane on horse liver alcohol dehydrogenase (HLADH)-catalyzed oxidation of the representative alcohol substrate cyclohexanol. With the exception of dimethylsulfoxide and dimethylformamide, all solvents tested are suitable for use as cosolvents with HLADH in the oxidative and reductive directions.

Enzymes in organic synthesis. 30. Reaction conditions – control of enantiomeric purities. Horse liver alcohol dehydrogenase-catalyzed reductions of 2-alkylcyclohexanones and their thiopyran analogs

1984 ◽  
Vol 62 (1) ◽  
pp. 77-80 ◽  
Author(s):  
J. Bryan Jones ◽  
Tetsuo Takemura
Keyword(s):  
Alcohol Dehydrogenase ◽  
Organic Synthesis ◽  
Reaction Conditions ◽  
Horse Liver Alcohol Dehydrogenase ◽  
Enantiomerically Pure ◽  
Liver Alcohol Dehydrogenase ◽  
Enzyme Substrate ◽  
Horse Liver ◽  
Substrate Ratio ◽  
Enzymes In Organic Synthesis

The effects of buffer, pH, reaction time, and [enzyme]/[substrate] ratio on the enantiomeric purities of the alcohol products of horse liver alcohol dehydrogenase-catalyzed reductions of (±)-α-alkylcyclohexanones and -tetrahydrothiopyranones have been studied. For poor substrates of this type, formation of enantiomerically pure products is assured when pH 8 and < 0.5 × 10−4 [E]/[S] ratio conditions are used.

Enzymes in organic synthesis. 14. Stereoselective horse liver alcohol dehydrogenase catalyzed oxidations of diols containing a prochiral centre and of related hemiacetals

1979 ◽  
Vol 57 (9) ◽  
pp. 1025-1032 ◽  
Author(s):  
J. Bryan Jones ◽  
Kar P. Lok
Keyword(s):  
Alcohol Dehydrogenase ◽  
Organic Synthesis ◽  
Initial Oxidation ◽  
Horse Liver Alcohol Dehydrogenase ◽  
Liver Alcohol Dehydrogenase ◽  
Horse Liver ◽  
Catalyzed Oxidation ◽  
Enzymes In Organic Synthesis ◽  
Hydroxyethyl Group

The asymmetric synthetic potential of horse liver alcohol dehydrogenase catalyzed oxidations of variously 3-substituted pentane-1,5-diols has been further delineated. The oxidations proceed with enantiotopic selectivity to give the corresponding (3S)-3-substituted valerolactones of up to 78% ee. The reactions occur via initial oxidation of the pro-S hydroxyethyl group, with the initially-formed hydroxyaldehydes undergoing further in situ enzyme-catalyzed oxidation in their hemiacetal forms to give the (3S)-lactones directly. The hemiacetal oxidation step is also stereoselective, with oxidation of the (4S)-enantiomer being much preferred. The size of the substituent at C-3 in the diols (C-4 in the hemiacetals) affects both the enantiotopic and enantiomeric specificity of the enzyme. Both types of stereospecificity are highest when the substituents are smallest, such as methyl or ethyl, and diminish progressively for diol or hemiacetal substrates bearing large aliphatic or aromatic substituents. All reactions were carried out on a preparative (up to 2 g) scale.

Sign in / Sign up

Export Citation Format

Share Document