beta-d-glucopyranosyl isocyanate in refluxing toluene. Deprotection of O-peracetylated N-beta-d-glucopyranosyl-N'-acyl ureas either under base (NaOMe in MeOH at or below rt) or under acid (KHSO(4) or AcCl in MeOH at rt) catalyzed transesterification conditions resulted in unavoidable partial cleavage of the N'-acyl moieties. Reaction of beta-d-glucopyranosylammonium carbamate with an isocyanate, isothiocyanate or isoselenocyanate
Synthesis of O -unprotected glycosyl selenoureas. A new access to bicyclic sugar isoureas
作者:José G. Fernández-Bolaños、Óscar López、Vı́ctor Ulgar、Inés Maya、José Fuentes
DOI:10.1016/j.tetlet.2004.03.143
日期:2004.5
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.