Asymmetric synthesis of amino acids by catalytic reduction of azlactones of substituted acylaminoacrylic acids. 8. Reductive aminolysis of 4-isopropylidene-oxazol-5-ones

Abstract

1. In the reaction of 4-isopropylideneoxazolones with S-(-)-α-phenylethylamine and hydrogen in the presence of a Pd catalyst in dimethoxyethane,α-phenylethylamide of N-benzoyl- or N-acetylvaline is obtained, preferentially in the SS-configuration, the N-acetyl derivative being formed with a higher stereoselectivity. 2. The reductive aminolysis process proceeds in the sphere of the catalytic complex, bypassing the stages of the formation of both unsaturated amide and saturated azlactone.