A Journey toward the Syntheses of γ-Amino-β-hydroxybutyric Acid (GABOB) and Carnitine

In this review, we discuss the synthetic approaches to γ-amino-β-hydroxybutyric acid (GABOB) and carnitine from 1980 to date. The unique structure and biological importance of these molecules have created much interest in various synthetic approaches over the last four decades by organic chemists from across the world. Most of the syntheses are asymmetric methods that involved chiral pool, enantioselective synthesis, enzyme resolution, or a chiral auxiliary as a source of chirality, and the biological significance of the molecules was also discussed. The compiled synthetic methods may fill the existence gap, simplify the complexity involved in the synthesis, and allow the best synthetic route to be found by comparison of all the methods. However, this review also will be useful to prepare similar kind of scaffolds present in various complex natural products.