Chiral intermediates were prepared by biocatalytic processes for the chemical synthesis of four pharmaceutical drug candidates. These include: (i) the microbial reduction of 3,5-dioxo-6-(benzyloxy) hexanoic ethyl ester to (3S,5R)-dihydroxy-6-(benzyloxy) hexanoic acid ethyl ester, an intermediate for a new anticholesterol drug; (ii) synthesis of (2R,3S)-(-)-N-benzoyl-3-phenyl isoserine ethyl ester, a taxol side-chain synthon; (iii) the microbial oxygenation of 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile to the corresponding (3S,4S) epoxide and (3S,4R)-transdiol, intermediates for synthesis of potassium channel opener; (iv) the biotransformation of (exo,exo)-7-oxabicyclo [2.2.1] heptane-2,3-dimethanol to the corresponding chiral lactol and lactone, intermediates for thromboxane A2antagonist.