Determination of the absolute configuration of sugar residues using gas chromatography. Method with potential for elimination of references.

The absolute configuration of a sugar can be determined by gas-liquid chromatography of the acetylated or trimethylsilylated dithioacetals from 1-phenylethanethiol. The isolation of both enantiomers of 1-phenylethanethiol is also described. Using the acetates and both thiol reagents the absolute configuration of C-2 can be determined, provided it is a hydroxyl group, with great certainty. A new way of determining the absolute configuration of sugars, without references, is thereby provided. The sugars analysed include aldoses, deoxyaldoses, 2-acetamido-2-deoxyaldoses and uronic acids. The analysis is made using columns with non-chiral stationary phase and the electron impact mass spectra of the acetylated and trimethylsilylated bis(1-phenylethyl)dithioacetals are described.