TaCl5-silicagel and TaCl5 as new Lewis acid systems for selective tetrahydropyranylation of alcohols and thioacetalisation, trimerisation and aldolisation of aldehydes.
摘要:
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.
A lipase-mediated synthesis of single enantiomeric trans-epoxides via convergence of racemic mixtures
作者:Takahiko Taniguchi、Kunio Ogasawara
DOI:10.1016/s0040-4039(99)00754-6
日期:1999.6
A new lipase-mediated methodology has been devised for the preparation of single enantiomeric trans-epoxides from unsymmetrical cis-olefin precursors via enantiomeric convergence of racemic intermediates. (C) 1999 Elsevier Science Ltd. All rights reserved.
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.
Deprotection of Tetrahydropyranyl Ethers with Montmorillonite K-10 Clay in Methanol
作者:Takahiko Taniguchi、Kohei Kadota、Adel S. ElAzab、Kunio Ogasawara