Synthesis of Felinine, 2-Amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic Acid

Several published synthesis procedures reported to lead to (±)-felinine, 2-amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic acid, a sulfur-containing urinary amino acid of cats (Felis domesticus), were evaluated for their yield. Most of the procedures were found to produce an amino acid isomeric with felinine and the structural assignment of this isomer has been determined as 2-amino-7-hydroxy-7-methyl-4-thiaoctanoic acid. The yield for the only evaluated synthesis procedure shown to produce felinine was found to be low. A new high-yielding method for the synthesis of (±)-felinine is presented.