Synthesis of O -unprotected glycosyl selenoureas. A new access to bicyclic sugar isoureas
摘要:
beta-D-Gluco and mannopyranosyl selenoureas have been prepared by coupling of the corresponding glycosylamines with phenyl isoselenocyanate in aqueous pyridine. Alkyl and aryl isoselenocyanates, and 1,4-phenylene diisoselenocyanate have been obtained from the corresponding formamides with an excess of triphosgene, black selenium and tricthylamine. Treatment of the O-unprotected beta-D-glucopyranosyl selenourea with aqueous oxygen pet-oxide afforded a 1,2-trans-fused bicyclic isourea. (C) 2004 Elsevier Ltd. All rights reserved.