Hydantoin → Alloisoleucine, D-

Participants

Reaction Steps

In another embodiment, as shown in Scheme 3, the invention is directed to a method for producing D-allo-isoleucine comprising converting (S)-2-methylbutyraldehyde to a diastereomeric mixture of D-allo-isoleucine hydantoin (5R-[(S)-1-methylpropyl]hydantoin) and L-isoleucine hydantoin (5S-[(S)-1-methylpropyl]hydantoin) under conditions whereby no significant racemization of the chiral center in (S)-2-methylbutyraldehyde occurs, followed by contacting said diastereomeric hydantoin mixture with a D-hydantoinase to stereoselectively hydrolyze any D-allo-isoleucine hydantoin in the mixture to the corresponding N-carbamoyl-D-allo-isoleucine. Preferably in the claimed method the contacting of the diastereomeric hydantoin mixture with a D-hydantoinase is carried out under conditions permitting the simultaneous epimerization of the chiral center at C-5 of the hydantoin. As discussed further below, 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-allo-isoleucine in high yield. The N-carbamoyl-D-allo-isoleucine is then decarbamoylated to produce D-allo-isoleucine.

Provenance & Evidence