A mild, efficient, and selective procedure for transprotection of acetonides to acetates catalyzed with HClO4–SiO2
摘要:
The transformation of acetonides into acetates is frequently required in synthetic chemistry. An efficient procedure for direct conversion of acetonides into acetates in the presence of HClO4-SiO2 under mild conditions was developed. The acetonides of primary hydroxy groups are directly converted to diacetates, and the anomeric acetonides of furanosides are stereoselectively transformed into the corresponding acetyl beta-D-furanosides with a 2-acetoxyisopropyl group. (C) 2009 Elsevier Ltd. All rights reserved.
An atom-efficient and powerful method for direct esterification of silyl ethers catalyzed by HClO4–SiO2
作者:Ti-Jian Du、Qin-Pei Wu、Hai-Xia Liu、Xi Chen、Yi-Nan Shu、Xiao-Dong Xi、Qing-Shan Zhang、Yun-Zheng Li
DOI:10.1016/j.tet.2010.12.028
日期:2011.2
An efficient and convenient procedure for direct esterification of alkyl and aryl silyl ethers with Ac2O and a catalyst system of perchloric acid immobilized on a silica gel (HClO4 SiO2) has been developed. The silyl protecting groups are directly replaced by acetyls and the protecting groups themselves are transformed into acetates as the sole byproducts, which can be readily recovered and converted back to silylchlorides, the original protecting agents, thus minimizing wastes. (C) 2010 Elsevier Ltd. All rights reserved.
A mild, efficient, and selective procedure for transprotection of acetonides to acetates catalyzed with HClO4–SiO2
The transformation of acetonides into acetates is frequently required in synthetic chemistry. An efficient procedure for direct conversion of acetonides into acetates in the presence of HClO4-SiO2 under mild conditions was developed. The acetonides of primary hydroxy groups are directly converted to diacetates, and the anomeric acetonides of furanosides are stereoselectively transformed into the corresponding acetyl beta-D-furanosides with a 2-acetoxyisopropyl group. (C) 2009 Elsevier Ltd. All rights reserved.
A general method for selective silylation of primary hydroxyl groups in carbohydrates and related compounds