An efficient synthesis of (S)-(−)-acromelobic acid (1) and (S)-(−)-acromelobinic acid (2) is described via asymmetric hydrogenation protocol. Asymmetric hydrogenation of dehydroamino acid derivative 23 using (R, R)-[Rh (DIPAMP)(COD)] BF4 catalyst followed by removal of the protective groups afforded (S)-(−)-acromelobic acid (1) in> 98% ee. The key intermediate 23 was prepared from citrazinic acid (8). The dehydroamino acid derivative ...
