Nucleophilic displacement reactions of some N-acetyl-N-aryl-β-d-xylopyranosylamines

The 4-O-methanesulphonyl (and toluene-p-sulphonyl), 3,4-di-O-methanesulphonyl (and toluene-p-sulphonyl), and 3,4-di-O-benzoyl-2-O-methanesulphonyl derivatives of N-acetyl-N-p-methoxyphenyl- and N-acetyl-N-p-chlorophenyl-β-d-xylopyranosylamine have been synthesised together with the N-acetyl-N-p-methoxyphenyl and N-acetyl-N-p-chlorophenyl derivatives of 3,4-di-O-benzoyl-2-O-methanesulphonyl-β-d-lyxopyranosylamine. The relative reactivity of the hydroxyl groups of the N-acetyl-N-aryl-β-d-xylopyranosylamines towards sulphonylation has been established. On heating the 2- and 4-mesylates of N-acetyl-N-aryl-β-d-xylopyranosylamines and the 2-mesylate of N-acetyl-N-aryl-β-d-lyxopyranosylamines with sodium azide in N,N-dimethylformamide or acetonitrile, either nucleophilic replacement of the mesyl groups of their solvolysis with participation of the N-acetyl group occurred. In this way, β-d-xylo compounds were converted into α-l-arabino and β-d-lyxo derivatives.