Abstract: The present invention relates to a novel enantioselective bioreduction using a yeast microorganism for the preparation of the chiral allylic alcohols of structural formula I (R is hydrogen or methyl) which are useful in the asymmetric synthesis of integrin &agr;v&bgr;3 receptor antagonists.

Abstract: A novel enzyme is provided. This enzyme is capable of reducing 4-haloacetoacetic acid esters to produce (S)-4-halo-3-hydroxybutyric acid esters with high optical purity. The enzyme was isolated from a microorganism belonging to the genus Kluyveromyces. Using the enzyme, (S)-4-halo-3-hydroxybutyric acid esters, which are useful as HMG-CoA reductase inhibitors, intermediates for synthesizing various medicines and agricultural chemicals, can be efficiently produced with high optical purity.

Abstract: A polyorganosiloxane polymer having a structure represented by one of the formulas(AB).sub.m C or [(AB).sub.m ].sub.n SiR.sub.(4-n)where the R groups are the same or different organic groups other than acrylic groups or groups co-curable therewith; A is a linear polyorganosiloxane segment containing between 3 and about 50 siloxane repeat units at least 3 of which are acrylic group containing repeat units represented by the formula ##STR1## where R.sup.1 is lower alkyl, the R.sup.2 groups are the same or different alkylene, alkyleneoxy or alkenylene groups, and y is 0-4; B is a polyorganosiloxane segment represented by the formula ##STR2## where x is an integer of at least 100; C is A or a triorganosilyl group; m is an integer of 1 or more; and n is 3 or 4.