Assignment of the configuration of optical isomers by gas chromatography by the use of asymmetric stationary phases. Absolute configuration of 2-amino-3-methylbutane and 2-amino-4-methylpentane

Abstract

The relationship, found previously, correlating the configuration and order of emergence of enantiomeric 2-N-trifluoroacetylaminoalkanes on carbonylbis-(N-L-valine isopropyl ester) has been confirmed for 2-amino-3-methylbutane (I) and 2-amino-4-methylpentane (II) by unambiguous synthesis of the L(R)-isomers. Confusion of assignment due to the effect of polar solvents on the sign of rotation of aminoalkanes has been cleared up for compounds (I) and (II). The findings of Brewster and his co-workers which correlate the sign of rotation [(–)–L(R)] have been shown to be correct, provided data referring to the neat liquid are considered, as specified by the authors. Cyclization of 2-aminoalkan-1-ols to aziridines, followed by hydrogenolysis, has been shown to lead to amines of known configuration (R : S 80 : 20) from the corresponding α-amino-acids.