Highly stereoselective synthesis of a seven-membered carbasugar via triisobutylaluminium promoted Claisen rearrangement
摘要:
2-Methylene-5-vinyl-tetrahydrofuran derivative 6 was obtained from alpha-D-glucose. Treatment of 6 with triisobutylaluminium (TIBAL) induced Claisen expansion reaction to give the seven-membered carbasugar derivative 7, which represents a new type of chiral building blocks. The rearrangement reaction has been proved to be highly stereoselective. (C) 2003 Elsevier Ltd. All rights reserved.
Highly stereoselective synthesis of a seven-membered carbasugar via triisobutylaluminium promoted Claisen rearrangement
摘要:
2-Methylene-5-vinyl-tetrahydrofuran derivative 6 was obtained from alpha-D-glucose. Treatment of 6 with triisobutylaluminium (TIBAL) induced Claisen expansion reaction to give the seven-membered carbasugar derivative 7, which represents a new type of chiral building blocks. The rearrangement reaction has been proved to be highly stereoselective. (C) 2003 Elsevier Ltd. All rights reserved.
Conversion of racemic allylic hydroperoxides into corresponding chiral 1/2,3-triols by using catalytic OsO$_{4}$ and chiral cinchona ligands in the absence of co-oxidant
作者:Haydar GÖKSU、Mehmet Serdar GÜLTEKİN
DOI:10.3906/kim-1411-68
日期:——
For the first time, removal of oxygen atoms from allylic hydroperoxide functionality and reintroduction to the double bond was achieved using catalytic OsO$_4}$ and chiral cinchona alkaloid derivatives in an acetone-water mixture to give corresponding chiral 1/2,3-triol with an enantioselectivity up to 99% ee. The hydroperoxide group was used as both a co-oxidant and a source of hydroxyl groups. This protocol is thought to have potential to provide opportunities for chiral synthesis of 1/2,3-triols from corresponding allylic hydroperoxides in the absence of co-oxidant in one stage for the first time in the literature.
Highly stereoselective synthesis of a seven-membered carbasugar via triisobutylaluminium promoted Claisen rearrangement
作者:Cai Jia、Yongmin Zhang、Lihe Zhang
DOI:10.1016/s0957-4166(03)00490-7
日期:2003.8
2-Methylene-5-vinyl-tetrahydrofuran derivative 6 was obtained from alpha-D-glucose. Treatment of 6 with triisobutylaluminium (TIBAL) induced Claisen expansion reaction to give the seven-membered carbasugar derivative 7, which represents a new type of chiral building blocks. The rearrangement reaction has been proved to be highly stereoselective. (C) 2003 Elsevier Ltd. All rights reserved.