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A NADPH-dependent benzil reductase (KRED1-Pglu) was used as recombinant enzyme for catalysing the reduction of different functionalised ketones. The reactions were carried out in the presence of a catalytic amount of NADP + and an enzyme-coupled transformation (oxidation of glucose catalysed by glucose dehydrogenase), for regenerating the cofactor and thus driving the reaction to completion. KRED1-Pglu showed remarkable versatility, being able to reduce different β-ketonitriles and α-haloketones at different pHs; notably, depending on the nature of the substrate, KRED1-Pglu can be used for efficient and clean enzymatic reduction, avoiding side-reactions due to the pH of the medium. The reduction generally occurred with high enantioselectivity, allowing the preparation of enantiomerically enriched β-hydroxynitriles and halohydrins in high yields; the stereochemical outcome of the reduction followed in all the cases the so-called Prelog's rule.

Ethyl secodione (1) has been enantioselectively reduced by using different biocatalysts for the preparation of ethyl secol (13R, 17S)-2a. The recombinant ketoreductase KRED1-Pglu converted the substrate with the highest reaction rate and stereoselectivity (ee > 98 %), whereas whole cells of Pichia minuta CBS 1708 showed the highest productivity. Stereoselective reduction of 1 provides the key chiral precursor for the synthesis of a number of hormonal contraceptives (i.e., desogestrel, norgestrel, gestodene).

The concurrent activity of ketoreductase and esterase of the yeast Pichia glycozyma allows the reduction of ketones and β-ketoesters to give hydroxyesters, hydroxy acids, or lactones as products.

An easy and efficient one-pot methodology for the preparation of aldoximes combines the enzymatic oxidation of corresponding primary alcohols using different acetic acid bacteria and in situ condensation of the resulting aldehydes with hydroxylamine.

Different protocols (lithium enolate reactions, fluoride catalyzed and Lewis acid mediated silyl ketene acetal reactions) were studied to achieve stereoselectivity in the aldol reactions of γ-thiobutyrolactone: in all cases benzaldehyde showed a striking peculiarity compared to aliphatic aldehydes.

Hemiacetal cleavage catalyst was designed, synthesized, and shown to be effective in promoting glycoaldehyde dimer dissociation and tetramethylglucose mutarotation

The reduction of the 2-keto acetals 1a and 1b by means of different microorganisms constitutes the biocatalytic access to optically active (46 to 100% ee) 2-hydroxy acetals, (S)-2a or (R)- and (S)-2b, representative compounds of a class of synthetically useful chiral building blocks.

The production of aliphatic and aromatic aldehydes by oxidation of primary alcohols was achieved with Gluconobacter oxydans DSM 2343. The biotransformation was optimised studying the oxidation of 2-phenyl-1-ethanol to 2-phenylacetaldehyde. A high molar conversion (95% chromatographic conversion, 83% of isolated yield) was obtained using cells grown on glycerol as the main carbon source and directly used in the cultural medium after 24 h at 28°C, pH 4.5 and 5 g L −1 substrate concentration. The conversion of structurally different primary alcohols was performed under these conditions allowing the chemoselective production of aldehydes, sometimes with very good yields.

An easy and efficient methodology for obtaining aldehydes or carboxylic acids by oxidation of the corresponding primary alcohols with acetic acid bacteria is reported. When the biotransformation is performed in water the acids are obtained; aldehydes can be accumulated by using a water/isooctane two-liquid phase system.

A variety of chiral auxiliaries R*OH were prepared and tested for levels of asymmetric induction control in the “Mukaiyama-aldol” reaction of chiral silyl ketene acetals. Structural features required for high levels of control are discussed.