In the presence of chiral diamines, the reaction between tin(II) enolates of ketones or 3-acyl-2-oxazolidones and thiosulfonates proceeds smoothly to give the corresponding β-keto sulfides with high enantioselectivity. Further, optically active epoxides are prepared from these β-keto sulfides.
The effects of C–S and C–Se bonds on torquoselectivity: stereoselective olefination of α-thio and α-selenoketones with ynolates
作者:Takashi Yoshikawa、Seiji Mori、Mitsuru Shindo
DOI:10.1016/j.tet.2009.08.060
日期:2009.10
Highly Z-selective olefination of acyclic alpha-thio and alpha-selenoketones with ynolates has been achieved, and the theoretical calculations of the transition states in the ring-opening of the intermediates, the beta-lactone enolates, revealed that the torquoselectivity was controlled by the secondary orbital interactions between the sigma orbital of the C-S bond or a lone pair orbital on the S and sigma* orbitals of the breaking C-O bond, and the sigma orbital of the breaking C-O bond or a lone pair orbital on the O on the ring and the sigma* orbitals of the C-S bond. The synthetic applications of the resulting olefins are also shown. (c) 2009 Elsevier Ltd. All rights reserved.
YURA TAKESHI; IWASAWA NOBUHARU; CLARK RICHARD; MUKAIYAMA TERUAKI, CHEM. LETT.,(1986) N 11, 1809-1812
作者:YURA TAKESHI、 IWASAWA NOBUHARU、 CLARK RICHARD、 MUKAIYAMA TERUAKI