Asymmetric Synthesis of Some Chiral Aryl and Hetero Aryl-Substituted β

Sixteen chiral -, -, and -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 - and -hydroxy esters 2d, 2e, and 2j-2s were obtained with high ee values and characterized by infrared, NMR (H-1 and C-13), mass spectrometry, chiral high-performance liquid chromatography, and specific rotation