The one step process, involving reactions between urea and protecting group free d-glucose, N-acetyl-d-glucosamine or d-xylose in acidic aqueous solution, furnishes the corresponding β-urea glycosides.
New nitrosourea derivatives are provided, which possess a high inhibitory activity against the leukemia and tumors with a low toxicity and which are useful for pharmaceutical purposes. The compounds have the formula ##STR1## wherein A represents a glycosyl group, a monovalent residue of methyl glucoside or of alditol, a N-substituted carbamoyloxyalkyl group or a hydroxy-substituted cyclohexyl group when n is 1, or A represents a tetravalent residue of ribostamycin when n is 4 and R represents a lower alkyl or halo-alkyl group and are prepared by treating a compound of the formula ##STR2## with a nitrosating agent.
A novel approach to the synthesis of urea glycosides in aqueous media has been explored. Steyermark's glucopyranosyl oxazolidinone was found to be a good synthon for anchoring glucosyl moieties onto amines and thiols. The present method was successfully applied to establish a new route for the synthesis of urea-tethered neoglycoconjugates and pseudooligosaccharides in water.