Oxidation of Methyl Trimethylsilyl Ketene Acetals to α-Hydroxyesters with Urea Hydrogen Peroxide Catalyzed by Methyltrioxorhenium
作者:Saša Stanković、James H. Espenson
DOI:10.1021/jo000212e
日期:2000.9.1
In the presence of catalytic amounts of MTO, methyltrioxorhenium, methyl trimethylsilylketeneacetals are oxidized with urea hydrogen peroxide to afford alpha-hydroxy and alpha-siloxy esters. On treatment with potassium fluoride, the alpha-hydroxy esters are obtained in high yields.
An improved synthesis of substituted cyclopropanone acetals and hemiacetals
作者:G. Rousseau、N. Slougui
DOI:10.1016/s0040-4039(00)81627-5
日期:1983.1
Cyclopropanation of ketene alkylsilylacetals or ketene disilylacetals with diethylzinc-methylene iodide leads to cyclopropanone acetals in high yield, and after methanolysis to cyclopropanonehemiacetals or hydrates.
Etude de la reaction chlorocarbene-acetals de cetenes
作者:G. Rousseau、N. Slougui
DOI:10.1016/s0040-4020(01)96367-7
日期:1985.1
with ketene alkylsilyl acetals. The best stereoselectivity was generally observed with the dimethyl tertiobutylsilyloxy group. With the chlorocarbenoid, using an E ketene acetal we obtained in majority (8̃0%) an E α,β-ethylenic ester and using a Z ketene acetal we obtained in majority (7̃0%) a Z α,β-ethylenic ester. In the case of the chloromethyl carbenoid the two ketene acetal isomers led to the same
Reaction of a chlorovinylcarbene with ketenealkyl silyl acetals. Synthesis of new α- and β-allenic carboxylates.
作者:N. Slougui、G. Rousseau
DOI:10.1016/s0040-4039(00)95384-x
日期:1987.1
Preparation and reactivity of the adducts of ketene alkylsilyl acetals with ethyl propiolate in the presence of titanium tetrachloride
作者:Alain Quendo、Syed Massarat Ali、Gerard Rousseau
DOI:10.1021/jo00051a039
日期:1992.12
The reaction of ketene alkylsilyl acetals with ethyl propiolate in the presence of TiCl4 led to intermediates whose reactivity was studied with electrophiles such as H2O, D2O, NBS, NCS, and PhSeCl to form glutaconate derivatives. Except in the case of the dimethylketene trimethylsilyl acetal, for which the reaction was stereospecific, with other ketene acetals the selectivity was lower. Similar results were observed in the reaction of these titanium intermediates with aldehydes and ketones. The results were interpretated as the formation of vinylic titanium intermediates (more stabilized in the case of the dimethylketene acetal) in equilibrium with the titanium allenolates.