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Esterhydrolases ( Esterases , Lipases ) are highly ( chemo-, regio- and enantio- ) selective biocatalysts for the transformation of racemic and achiral substrates into enantiomerically pure compounds. Numerous examples for their application in the preparation of synthetically useful chiral auxiliaries and building blocks for flavour compounds, pheromones and several pharmaceuticals including 8- adrenergic blockers, antidepressants and ACE inhibitors are presented. The close relationship between biological activity and absolute configuration both in natural products and synthetic materials ( e.g. drugs , agrochemicals ) has prompted considerable efforts regarding the synthesis of enantiomerically pure compounds. They are widely used as - chiral building blocks for biologically active compounds, - auxiliaries and stationary phases for analytical purposes or - chiral ligands for the design of enantioselective catalysts Next to other methods , e.g. classical resolutions via diastereoisomers, asymmetric and I' chiral pool" syn- theses enzymes - nature's chiral catalysts - have emerged as highly effective 'I reagents " for their prepa- ration. They display highly attractive properties for the solution of synthetic organic problems, some of which are summarized in Fig 1.

Esterhydrolases ( Esterases , Lipases ) are highly ( chemo-, regio- and enantio- ) selective biocatalysts for the transformation of racemic and achiral substrates into enantiomerically pure compounds. Numerous examples for their application in the preparation of synthetically useful chiral auxiliaries and building blocks for flavour compounds, pheromones and several pharmaceuticals including 8- adrenergic blockers, antidepressants and ACE inhibitors are presented. The close relationship between biological activity and absolute configuration both in natural products and synthetic materials ( e.g. drugs , agrochemicals ) has prompted considerable efforts regarding the synthesis of enantiomerically pure compounds. They are widely used as - chiral building blocks for biologically active compounds, - auxiliaries and stationary phases for analytical purposes or - chiral ligands for the design of enantioselective catalysts Next to other methods , e.g. classical resolutions via diastereoisomers, asymmetric and I' chiral pool" syn- theses enzymes - nature's chiral catalysts - have emerged as highly effective 'I reagents " for their prepa- ration. They display highly attractive properties for the solution of synthetic organic problems, some of which are summarized in Fig 1.

Publisher Summary This chapter summarizes important types of screening experiments commonly to be executed in laboratories engaged in the synthetic applications of lipases. Faced with the necessity of finding the most suitable lipase for the solution of a synthetic problem, organic chemists usually have to address one of the following: (1) adopting an “established” lipase with known selectivities and substrate tolerance toward the transformation of a given substrate; (2) finding the best lipase among commercially available enzymes for the conversion of a given target molecule; (3)finding a new lipase for the conversion of a defined target molecule; and (4) most likely of interest mainly to enzyme producers and in an attempt to make new lipases with interesting properties available to the scientific community, screening lipases—or microorganisms producing such enzymes—for their substrate tolerance, enantioselectivity, solvent dependence, and other properties. The chapter aims to inform the important issues related to the application of these enzymes.

(R) and (S)-t-butyloxirane [(R)- and (S)-3] have been prepared in high enantiomeric purity from racemic t-butyloxirane (±)-3 by an enzymatic route. (S)-3 has been used for the preparation of the chiral β-amino alcohols (R)- and (S)-1,2, which are catalysts for the enantioselective addition of dialkylzinc reagents to aldehydes.