Lewis Base Catalyzed, Enantioselective Aldol Addition of Methyl Trichlorosilyl Ketene Acetal to Ketones
作者:Scott E. Denmark、Yu Fan、Martin D. Eastgate
DOI:10.1021/jo0506276
日期:2005.6.1
addition of an acetate enolate equivalent to ketones is described. Methyl trichlorosilyl ketene acetal reacts with a wide range of ketones in the presence of pyridine N-oxide to afford the aldol addition products in excellent yields. Chiral 2,2‘-pyridyl bis-N-oxides bearing various substituents at the 3,3‘- and 6,6‘-positions also provide excellent yields of the aldolproducts with variable enantioselectivities
Highly regioselective addition of an ester enolate equivalent to α,β-unsaturated ketones: selective formation of both isomers derived from 1,2- and 1,4-additions using α-stannyl ester with additives
作者:Makoto Yasuda、Yozo Matsukawa、Keishi Okamoto、Toshifumi Sako、Noriko Kitahara、Akio Baba
DOI:10.1039/b004817h
日期:——
The reaction of α-stannyl ester with α,β-unsaturated ketones in the presence of stannous chloride (SnCl2) and chlorosilanes (Me3SiCl or Me2SiCl2) gave 1,2- and 1,4-addition products, respectively.
A one-pot Reformatsky/cyclopropanation sequence induced by diethylzinc allows the transformation of omega-unsaturated ketones and aldehydes to omega-cyclopropyl alcohols.