Monoacetylation of Carbohydrate Diols via Transesterification with Ethyl Acetate
作者:Xuyu Liu、Bernd Becker、Matthew A. Cooper
DOI:10.1071/ch12518
日期:——
Monoacetylation of secondary diols in protected monosaccharides was achieved with ethylacetate as acyl donor and sodium tert-butoxide as a base. The regioseletivity of the reaction varied depending on the substrate. This new method provides a simple, fast, and efficient method to access selectively acetylated carbohydrates that is compatible with acid-sensitive protecting groups.
Acylation of carbohydrates over Al2O3: preparation of partially and fully acylated carbohydrate derivatives and acetylated glycosyl chlorides
作者:Pallavi Tiwari、Anup Kumar Misra
DOI:10.1016/j.carres.2005.11.035
日期:2006.2
protocol does not require the addition of any base or activator. This methodology has been further extended to the selective acylation of carbohydrate diols and the one-pot preparation of acetylated glycosyl chlorides directfrom free reducingsugars. The yields obtained in most of the cases are excellent.
Organosilicon-mediated regioselective acetylation of carbohydrates
作者:Yixuan Zhou、Olof Ramström、Hai Dong
DOI:10.1039/c2cc31556d
日期:——
Organosilicon-mediated, regioselective acetylation of vicinal- and 1,3-diols is presented. Methyl trimethoxysilane or dimethyl dimethoxysilane was first used to form cyclic 1,3,2-dioxasilolane or 1,3,2-dioxasilinane intermediates, and subsequent acetate-catalyzed monoacylation was efficiently performed by addition of acetic anhydride or acetyl chloride under mild conditions. The reaction exhibited
In Ag2O‐mediated benzylation, the addition of a catalytic amount of KI can greatly improve reactivity. This is usually attributed to the formation of a more reactive iodo‐substituted electrophile. However, our studies show this to be due to the enhancedbasicity of Ag2O through coordination of soft iodide anions to the silver atom, and show KI to be an initiator. A catalytic amount of Ag2O and NaBr
Site‐Selective Acylation of Pyranosides with Immobilized Oligopeptide Catalysts in Flow
作者:Alexander Seitz、Raffael C. Wende、Peter R. Schreiner
DOI:10.1002/chem.202203002
日期:2023.3.28
We describe the immobilization of oligopeptide catalysts and their use in the site-selective acetylation of different monosaccharides. The catalysts are easy to synthesize, can easily be reused for several reactions, and are able to perform well in first continuous flow experiments.