Patent ID: 7462738

Claim:
A process for preparing (R)-(+)-3-(carbamoylmethyl)-5-methylhexanoic acid or a salt thereof having the formula comprising: a) asymmetrically ring opening 3-isobutylglutaric anhydride to obtain a chiral ester having the formula: b) amidating the chiral ester to obtain a (R)-(+)-3-(carbamoylmethyl)-5-methylhexanoic acid salt having the formula and, optionally, c) converting the (R)-(+)-3-(carbamoylmethyl)-5-methylhexanoic acid salt to (R)-(+)-3-(carbamoylmethyl)-5-methylhexanoic acid, wherein R 1 and R 2 are independently selected from the group consisting of: H, aliphatic, branched or cyclic C 1 to C 12 hydrocarbyl, C 6 to C 9 aromatic hydrocarbyl and CO 2 H, and M is either H or NH 4 + .