title: Selective pivaloylation and diphenylacetylation of cyclomalto-oligosaccharides.
abstract: Regioselective acylation of cyclomalto-oligosaccharides was achieved using pivaloyl and diphenylacetyl chlorides. The reaction of cyclomaltohexaose (1) with pivaloyl chloride gave the hexakis(2,6-di-O-pivaloyl) derivative 19 in 66% yield. Similar reaction with cyclomalto-heptaose (2) led to the octakis(2I,6I,6II,6III,6IV,6V,6VI ,6VII-O-pivaloyl) 26 and the 17 heptakis(6-O-pivaloyl) derivatives in 34 and 26% yields, respectively. The octakis(6-O-pivaloyl) derivative 18 was the only compound isolated (72%) in the reaction of pivaloyl chloride with cyclomalto-octaose (3). Diphenylacetylation of 1-3 gave the symmetrical (20-22) and the non-symmetrical (27-29) per(6-O-diphenylacetyl) esters as major and minor products, respectively.
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Santoyo-González
authors.forename: J
authors.initials: J
authors.lastname: Isac-García
authors.forename: A
authors.initials: A
authors.lastname: Vargas-Berenguel
authors.forename: R
authors.initials: R
authors.lastname: Robles-Díaz
authors.forename: F G
authors.initials: FG
authors.lastname: Calvo-Flores
mesh_terms: D000107:Acetylation; D002240:Carbohydrate Sequence; D003505:Cyclodextrins / Q000737:chemistry*; D004158:Diphenylacetic Acids / Q000737:chemistry*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*; D010421:Pentanoic Acids / Q000737:chemistry*; D047391:alpha-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D004158:Diphenylacetic Acids; D009844:Oligosaccharides; D010421:Pentanoic Acids; D047391:alpha-Cyclodextrins; C059099:pivaloyl chloride; C032613:alpha-cyclodextrin