The trimethylsilylation of xylose and the nuclear magnetic resonance spectra of the major products

Abstract Four products have been detected from the reaction of trimethylsilyl chloride with xylose. The two major ones obtained on etherifying a mutarotated mixture of xylose isomers have been isolated and characterized with the aid of NMR spectroscopy as the fully substituted trimethylsilyl pyranose derivatives. It is suggested that the evidence from these and related studies indicates that pyranose rings are somewhat flattened by the introduction of axial groupings. The effect of the trimethylsilyloxy grouping on the NMR signals of α-hydrogens has been compared with that of the acetoxy grouping.