2 oxoglutaric acid article 4 biocatalyst 4 enantiomer 4 4 hydroxybutyric acid 2 Biotransformation 2 Cells 2 Dialkyl 2-oxoglutaric acid esters 2 Dialkyl esters 2 Enantiomers 2 Enantioselectivity 2 Esters 2 Oxoglutaric acid 2 Rhodotorula 2 Rhodotorula minuta 2 Yeast 2 acidification 2 alkylation 2 biotransformation 2 catalysis 2 decarboxylation 2 derivatization 2 drug synthesis 2 enantioselectivity 2 enzyme mechanism 2 ester derivative 2 esterification 2 fungal enzyme 2 hydrolysis 2 lactone derivative 2