Hydantoin → D-Isoleucine

Participants

Reaction Steps

Methods for producing single diastereomers of isoleucine in high stereochemical purity are provided. D-isoleucine is produced by converting (R)-2-methylbutyraldehyde to a diastereomeric mixture of D-isoleucine hydantoin and L-allo-isoleucine hydantoin (5S-[(R)-1-methylpropyl]hydantoin) under conditions whereby no significant racemization of the chiral center in (R)-2-methylbutyraldehyde occurs, followed by contacting said diastereomeric hydantoin mixture with a D-hydantoinase to stereoselectively hydrolyze any D-isoleucine hydantoin in the mixture to the corresponding N-carbamoyl-D-isoleucine, preferably under conditions permitting the simultaneous epimerization of the chiral center at C-5 of the hydantoin. The simultaneous epimerization permits the reaction to be carried out to substantial completion so that the diastereomeric hydantoin mixture is converted to N-carbamoyl-D-isoleucine in high yield. The N-carbamoyl-D-isoleucine is then decarbamoylated to produce D-isoleucine. Similar procedures are used to produce single diastereomers of L-isoleucine, L-allo-isoleucine, and D-allo-isoleucine.

Provenance & Evidence