Asymmetric .ALPHA.-substituted phenethylamines. I. Synthesis of optically pure 1-aryl-N-(2'-hydroxy-1'-isopropylethyl)-2-phenylethylamines.

Optically pure 1-aryl-N-(2'-hydroxy-1'-isopropylethyl)-2-phenylethylamines (3a-c) were synthesized by the reactions of N-(2-hydroxy-1-isopropylethyl) arylmethylideneamines (2a-c) with benzylmagnesium chloride. The diastereomers (5a-c) were prepared from N-(2-hydroxy-1-isopropylethyl) phenylethylideneamine (4) and aryllithium compounds. The optical purity of 3a was elucidated and the absolute configuration was determined by synthesis via an alternative route. The characteristic methyl signals in the nuclear magnetic resonance (NMR) spectra suggested the configurations of the chiral amines (3a-c and 5a-c).