The inexpensive solid acid, montmorillonite K-10, is shown to be an efficient catalyst for the per-O-acetylation of several mono-, di- and trisaccharides. The pyranose forms accounted for 75- 100% of the acetylated products.

Pallooru Muni Bhaskar

Duraikkannu Loganathan

disaccharide

monosaccharide

Montmorillonite

trisaccharide

ACETYLATION

article

carbohydrate metabolism

catalysis

catalyst

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Per-O-acetylation of sugars catalysed by montmorillonite K-10

Tetrahedron Letters

H-Beta zeolite, a microporous solid acid, is demonstrated to be an efficient catalyst for the selective deprotection of cyclic as well as acyclic O-isopropylidene sugar acetals derived from d-glucose, d-xylose, d-mannose, and d-mannitol in aqueous MeOH at room temperature. A notable observation is the conversion of d-mannitol triacetonide into 1,2:3,4-di-O-isopropylidene-d-mannitol (48%) and 3,4-O-isopropylidene-d-mannitol (36%) brought about in 6 h by H-beta zeolite and the non-occurrence of any hydrolysis in the case of H-ZSM-5 catalyzed reaction in 24 h under the same conditions. © 2008 Elsevier Ltd. All rights reserved.

Carbohydrate Research

Zeolite catalyzed selective deprotection of di- and tri-O-isopropylidene sugar acetals

Reported is an attractive and environmentally friendly method for the synthesis of the title compounds in moderate yield using inexpensive 1,2,3,4,6-penta-O-acetyl-β-d-gluco- and galactopyranoses as sugar donors, five different phenols as acceptors and H-β zeolite as the catalyst. The yield (23-28%) of aryl 3,4,6-tri-O-acetyl-α-d-glycopyranosides obtained in this single-step procedure is considerably higher than that obtained using previously reported methods. Treatment of an orthoacetate, 3,4,6-tri-O-acetyl- [1,2-O-(1-p-fluorophenoxyethylidene)]-α-d-glucopyranose, with p-fluorophenol under the same solvent-free reaction conditions also led to the formation of the title compounds in similar yield and composition. X-ray crystallographic analysis of phenyl 3,4,6-tri-O-acetyl-α-d-glucopyranoside and p-fluorophenyl 3,4,6-tri-O-acetyl-α-d-glucopyranoside showed that the molecular packing is stabilized by C-H⋯O, C-H⋯π and C-H⋯F interactions, in addition to regular hydrogen bonding patterns. © 2005 Elsevier Ltd. All rights reserved.

Stereoselective single-step synthesis and X-ray crystallographic investigation of acetylated aryl 1,2-trans glycopyranosides and aryl 1,2-cis C2-hydroxy-glycopyranosides

Among the six different zeolites examined, H-beta is demonstrated to be a highly efficient and selective catalyst for the per-O-acetylation of various mono-and disaccharides and methyl glycosides.

Synlett

H-Beta zeolite as an efficient catalyst for per-O-acetylation of mono- and disaccharides

Tetrahedron

Iodine: A versatile reagent in carbohydrate chemistry IV. Per-O-acetylation, regioselective acylation and acetolysis

Acetylation of carbohydrates using ferric chloride in acetic anhydride

Journal	Tetrahedron Letters
ISSN	00404039
Open Access	No