Novel Synthesis of (S)-(-)-Chroman-2-carboxylic Acid, Vitamin E Precursor

Article abstract of DOI:10.1246/cl.1989.465

A new strategy to the synthesis of (S)-(-)-chroman-2-carboxylic acid, a pivotal intermediate possessing the absolute configuration required for the construction of α-tocopherol, was disclosed by utilizing asymmetric halolactonization of acylproline.Debromination followed by acidic hydrolysis directly afforded the title compound in 98percent enantiomer excess.