Mild acetalisation of mono and dicarbonyl compounds catalysed by titanium tetrachloride. Facile synthesis of β-keto enol ethers

A Clerici, N Pastori, O Porta

Index: Clerici, Angelo; Pastori, Nadia; Porta, Ombretta Tetrahedron, 2001 , vol. 57, # 1 p. 217 - 225

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Citation Number: 84

Abstract

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 β-keto enol ethers. Additionally, aryl ketones and acyclic ketones failed to react. β-keto aldehydes can be monoprotected either as β-keto enol ethers or β-keto dimethyl acetals depending on the reaction time and catalyst amount. ...