Synthesis of Enantiomerically Pure (S)-(-)-Propranolol from Sorbitol

Article abstract of DOI:10.1016/S0957-4166(00)82209-0

Synthesis of enantiomerically pure (S)-(-)-propanolol, the most active optical isomer of widely used β-Sympatholyticum, was achieved in high optical yield from starting sorbitol, an inexpensive and easily accessible carbohydrate.Via regioselective protection and coupling of α-naphthol, the key intermediate 5 was obtained.Deprotection of the intermediate acetals and successive oxidative degradation followed by some simple conversion steps lead to the formation of (S)-(-)-propranolol with high optically purity.Key Words: β-Sympatholyticum; Sorbitol; Asymmetric Synthesis; Acetals; Regioselective