Abstract: In the present invention new compounds of formula II, in enantiomerically enriched forms, are described for the first time, where R1 is chloroalkyl. The present invention also includes several new enzymatic processes for the resolution of the enantiomers of the aforementioned carbonates of formula II from the corresponding racemic mixture. The transformation of these carbonates into zopiclone enantiomerically enriched, constitutes an additional aspect of the invention.

Abstract: A biocatalytic process to obtain optically enriched precursors of trans-4-(4-fluorophenyl)-3-hydroxymethylpiperidines, based on the enzymatic resolution of racemic derivatives of general formula III (where R3 is preferably phenyl or benzyl) using cyclic anhydrides or the Meldrum's acid (2,2-dimethyl-1,3-dioxane-4,6-dione) as acylating agents of the hydroxyl group. Depending on the enzyme and the chosen reaction conditions, either of the two enantiomers may be obtained with high enantiomeric purity. These compounds are important intermediates in the synthesis of the paroxetine anti-depressive agent.

Abstract: The present invention is directed to methods for the preparation of 3′-O and 5′-O-levulinyl nucleosides from common precursors using an enzymatic approach.

Abstract: The present invention is directed to methods for the preparation of 3′-O and 5′-O-levulinyl nucleosides from common precursors using an enzymatic approach.

Abstract: A biocatalytic process to obtain optically enriched derivatives of trans-4-(4-fluorophenyl)-3-hydroxymethylpiperidines, based on the enzymatic resolution of racemic precursors of formula III (where R3 is preferably phenyl or benzyl) by acylation of the hydroxyl group. Depending on the enzyme and the reaction conditions, either of the two enantiomers may be obtained with high enantiomeric purity. These compounds are important intermediates in the synthesis of the paroxetine anti-depressive agent.

Abstract: The present invention is directed to methods for the preparation of 3′—O and 5′—O—levulinyl nucleosides from common precursors using an enzymatic approach.

Abstract: A method for predominantly preparing the enantiomer (R)-(+)-5-(phenyl)hydroxymethyl-1-methyl-1H-pyrazole, (R)-(+)-1, by separating the racemate (+)-5-(phenyl)hydroxymethyl-1-methyl-1H-pyrazole of formula (1), comprising the series of steps of using a lipase or material derived therefrom having enzymatic activity in a transesterification reaction, as well as hydrolysing the resulting ester, (S)-(-)-5-(phenyl)alkylcarbonyloxymethyl-1-methyl-1H-pyrazole, of formula (S)-(-)-4, wherein R.sub.1 is a methyl or ethyl radical.