Treatment of diethylthioacetals with two equivalents of trityl methyl ether in the presence of a catalytic amount of trityl perchlorate, and successive quenching with aqueous sodium hydrogencarbonate gave parent carbonyl compounds, hydrolyzed products, in high yields under mild conditions. According to this method, it is also possible to hydrolyze diethylthioacetals selectively even when another thioacetal
Stepwise Reduction of Acetals to the Corresponding Hydrocarbons. A Mild and Effective Transformation via Carbinyl Bromides
作者:Takeshi Oriyama、Yuichi Ichimura、Gen Koga
DOI:10.1246/bcsj.64.2581
日期:1991.8
Stepwise reduction of two alkoxyl groups in acetal was effected by the action of triethylsilane along with acetyl bromide and SnBr2 and then of tributyltin hydride (or lithium aluminium hydride) providing methyl or methylene compounds in good yields under very mild conditions.
Development and Mechanistic Studies of the Iridium‐Catalyzed C−H Alkenylation of Enamides with Vinyl Acetates: A Versatile Approach for Ketone Functionalization
作者:Bo Zhou、Xiaotian Qi、Peng Liu、Guangbin Dong
DOI:10.1002/anie.202107331
日期:2021.9.13
Ketone functionalization is a cornerstone of organic synthesis. Herein, we describe the development of an intermolecular C−H alkenylation of enamides with the feedstock chemical vinyl acetate to access diverse functionalized ketones. Enamides derived from various cyclic and acyclic ketones reacted efficiently, and a number of sensitive functional groups were tolerated. In this iridium-catalyzed transformation
Mild acetalisation of mono and dicarbonyl compounds catalysed by titanium tetrachloride. Facile synthesis of β-keto enol ethers
作者:Angelo Clerici、Nadia Pastori、Ombretta Porta
DOI:10.1016/s0040-4020(00)01001-2
日期:2001.1
The use of TiCl4, as a catalyst for the acetalisation, at room temperature, of carbonyl compounds is reported. Cyclic ketones and cyclic 1,4-diketones easily afford dimethyl acetals, but cyclic 1,3-diketones give beta -keto enol ethers. Additionally, aryl ketones and acyclic ketones failed to react. beta -keto aldehydes can be monoprotected either as beta -keto enol ethers or beta -keto dimethyl acetals depending on the reaction time and catalyst amount. Some mechanistic features are accounted for. (C) 2000 Elsevier Science Ltd. All rights reserved.