Use of 2-phenylsulphonyl cyclic ethers in the preparation of tetrahydropyran and tetrahydrofuran acetals and in some glycosidation reactions.
作者:Dearg S. Brown、Steven V. Ley、Sadie Vile、Mervyn Thompson
DOI:10.1016/s0040-4020(01)86389-4
日期:1991.1
2-Phenylsulphonyl cyclic ethers undergo facile displacement of the sulphonyl group by alcohols, in the presence of magnesium bromide etherate and sodium bicarbonate in tetrahydrofuran, to give goodyields of the corresponding acetals.
A mild and efficient method for chemoselective deprotection of acetonides by bismuth(III) trichloride
作者:N.Raghavendra Swamy、Y Venkateswarlu
DOI:10.1016/s0040-4039(02)01809-9
日期:2002.10
Acetonides undergo chemoselective deprotection to afford the corresponding 1,2-diols in excellent yields using bismuthtrichloride in acetonitrile/dichloromethane at ambient temperature.
Polymer-Supported Ferric Chloride as a Heterogeneous Catalyst for Chemoselective Deprotection of Acetonides
作者:M. Chari、K. Syamasundar
DOI:10.1055/s-2005-861817
日期:——
Acetonides undergo chemoselective deprotection to afford the corresponding 1,2-diols in excellent yields using polymer (PVP)-supported ferric chloride as a heterogeneous catalyst in acetonitrile-dichloromethane at room temperature.
TaCl5-silicagel and TaCl5 as new Lewis acid systems for selective tetrahydropyranylation of alcohols and thioacetalisation, trimerisation and aldolisation of aldehydes.
TaCl5 adsorbed on silicagel has been utilized for the first time as Lewis acid catalyst for protection of aldehydes and alcohols as thiocetals and THP ethers respectively. Similarly TaCl5 has been exploited as an useful Lewis acid for chemoselective trimerisation and/or aldolisation of aldehydes. (C) 1997 Elsevier Science Ltd.