Patent ID: 8324273

Claim:
A compound chosen from: (1R)-1-methyl-2-phenylcarbonyloxyethyl (2S)-2-amino-3-[3,4-bis(ethoxycarbonyloxy)phenyl]propanoate hydrochloride; (1R,2R)-2-acetyloxy-1-methylpropyl (2S)-2-amino-3-[3,4-bis(ethoxycarbonyloxy)phenyl]propanoate-hydrochloride-; (1R,2R)-1-methyl-2-(2-methylpropanoyloxy)propyl (2S)-2-amino-3-[3,4-bis(ethoxycarbonyloxy)phenyl]propanoate hydrochloride; (1R,2R)-2-isopropoxycarbonyloxy-1-methylpropyl (2S)-2-amino-3-[3,4-bis(ethoxycarbonyloxy)phenyl]propanoate hydrochloride; (2R)-2-acetyloxypropyl (2S)-2-amino-3-[3,4-bis(ethoxycarbonyloxy)phenyl]propanoate hydrochloride; (1R)-2-acetyloxy-1-methylethyl (2S)-2-amino-3-[3,4-bis(ethoxycarbonyloxy)phenyl]propanoate hydrochloride; (1R)-2-acetyloxy-1-methylethyl (2S)-2-amino-3-[3,4-bis(ethoxycarbonyloxy)phenyl]propanoate hydrogen fumarate; (1R)-1-methyl-2-(2-methylpropanoyloxy)ethyl (2S)-2-amino-3-[3,4-bis(ethoxycarbonyloxy)phenyl]propanoate hydrochloride, and other pharmaceutically acceptable salts of any of the foregoing.