Conformations and configurations of some chlorosulfated α- and β-D-pentopyranosyl chlorides

The conformations of the fully chlorosulfated α- and β-D-xylopyranosyl and lyxopyranosyl chlorides in deuteriochloroform solution have been studied by proton magnetic resonance spectroscopy. The analysis of the spectra indicated that the anomeric effect is a factor in determining the conformational preference of the pentopyranosyl chlorides, as each existed predominantly in the conformation in which the chlorine was axial. A number of factors involving the synthesis of these chlorides have also been elucidated.