Isothiocyanatoulosonates, a new type of glycosyl isothiocyanate useful for the stereocontrolled synthesis of thiohydantoin spironucleosides

Thiohydantoin spironucleosides and N-alkyl, aryl and glycosyl derivatives are prepared in a stereocontrolled manner, by reaction of ammonia, and of alkyl-, aryl- and glycosyl-amines with a new class of isothiocyanato sugar: the methyl 2-deoxy-2-isothiocyanatohex-2-ulofura(pyra)nosonates. The reaction produces an intermediate thioureido derivative, which spontaneously cyclates to give the spironucleoside in high yield. Alternatively, the same spironucleosides are prepared from methyl 2-amino-2-deoxy-hex-2-ulofura(pyra)nosonates and alkyl-, aryl- and glycosyl isothiocyanates. Some of the prepared compounds have the structure of N-nucleoside of spirothiohydantoins.