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.
acetylation of vicinal and 1,3-diols is presented. Herein, the acetylation of the hydroxyl group with acetic anhydride can be activated by the formation of H-bonds between the hydroxyl group and anions. The reaction exhibits high regioselectivity when a catalytic amount of tetrabutylammonium acetate is employed. Mechanisticstudies indicated that acetate anion forms dual H-bonding complexes with the diol
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