A Practical and Stereoconservative Synthesis of (R)-3-Amino-4-(trimethylammonio)butanoate [(R)-Aminocarnitine], and Its Trimethylphosphonium and Simple Ammonium Analogues Starting from D-Aspartic Acid

We have developed a new stereospecific synthesis of (R)‐aminocarnitine using D‐aspartic acid as the starting material. This strategy, which is simple and amenable to an industrial scale‐up, gives the target compound in six steps and in fairly good overall yields (41%). Other aminocarnitine related molecules such as optically pure (R)‐3‐amino‐4‐(trimethylphosphonio)butanoic acid and (R)‐3,4‐diaminobutanoic acid dihydrochloride have also been prepared according to the same synthetic strategy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)