Stereoselective electrogeneration of (E)-4-alkoxy-2-phenyl-5-chloro-2-oxazolines by cathodic reduction of N-(1-alkoxy-2,2,2-trichloroethyl)benzamides

摘要

The first method for the synthesis of the title compounds has been established. Quantitative reactions of benzamides with chloral hydrate provided chloralbenzamides which were efficiently converted to N-(1,2,2,2-tetrachloroethyl)amides by treatment with phosphor-us pentachloride. These compounds reacted selectively with alcohols under mild conditions to give N-(1-alkoxy-2,2,2-trichloroethyl)benzamides in high yields which were stereoselectively transformed to (E)-4-alkoxy-2-aryl-5-chloro-2-oxazolines in fair to good yields by electrochemical reduction under constant cathodic potential in an aprotic medium. (C) 2003 Elsevier Ltd. All rights reserved. [References: 30]