Asymmetric Synthesis of Some Chiral Aryl and Hetero Aryl-Substituted β-, γ-, δ-Hydroxy Esters

Sixteen chiral β-, γ-, and δ-hydroxy esters with aryl, substituted aryl, and heteroaryl groups 2a–2s were synthesized by the asymmetric reduction of their corresponding keto esters 1a–1s as chiral pure reference compounds and starting materials. The asymmetric reduction was achieved by (R)-Me-CBS-oxazaborolidine. Ten new chiral γ- and δ-hydroxy esters 2d, 2e, and 2j–2s were obtained with high ee values and characterized by infrared, NMR (1H and 13C), mass spectrometry, chiral high-performance liquid chromatography, and specific rotation.