Abstract: The present invention provides a novel approach for the preparation of fatty alcohol esters of ?-hydroxy carboxylic acids. In one form of the invention, the target fatty alcohol ester of ?-hydroxy carboxylic acid is produced by converting a lower alkyl ester of ?-hydroxy carboxylic acid into a fatty alcohol ester of ?-hydroxy carboxylic acid via alcoholysis (i.e., transesterification). The transesterification process is an equilibrium reaction, catalyzed chemically (i.e., with acids or bases) or enzymatically, that is shifted in the desired direction to produce the desired product. One preferred way of shifting the reaction in the direction of the desired product is by reducing the concentration of one of the products (e.g., distillation of a lower-boiling alcohol as soon as it is formed). Another preferred way of shifting the reaction in the direction of the desired product is by increasing the concentration of one of the reactants (e.q., adding more of the starting ester).

Abstract: A process for the large-scale chemoenzymatic production of (6S)-5-methyl-5,6,7,8-tetrahydrofolic acid, also known as (6S)-5-methylTHFA, the process comprising the steps of: (1) reducing folic acid (FA) so as to yield dihydrofolic acid (DHFA); (2) stereoselectively reducing DHFA with dihydrofolate reductase (DHFR) in the presence of NADP/NADPH, glucose and GluDH so as to yield (6S)-THFA; (3) converting (6S)-THFA to (6S)-5-methylTHFA; and (4) isolating (6S)-5-methylTHFA.