Gopalaiah, Kovuru (2004) Oxalic acid:A very useful bronsted acid in organic synthesis. In: SYNLETT (15). pp. 2838-2839.
Restricted to Registered users only
Download (121Kb) | Request a copy
(A) Oxalic acid is an efficient reagent for the Beckmann reaction - a variety of ketoximes are converted into the corresponding secondary amides by classical anti-periplanar migration upon heating to ca. 100 °C, and aldoximes afford the corresponding nitriles. The procedure offers high yield of the desired products, gaseous byproducts $(CO + CO_2)$ and the absence of reaction solvent. (B) Anhyd. oxalic acid is an excellent mediator for one-pot transformation of ketones to amides in the presence of hydroxylamine hydrochloride. The method is effective for various arom. and aliph. ketones, and provides excellent yield of the products. (C) In the presence of aq. oxalic acid, enol ethers undergo expeditious hydrolysis to the corresponding ketones without concomitant migration of the double bond. In contrast, use of a mineral acid typically gives the conjugated ketone. This method offers considerable advantage in terms of regioselectivity of the product.
|Item Type:||Journal Article|
|Additional Information:||The copyright of this article belongs to Georg Thieme Verlag.|
|Department/Centre:||Division of Chemical Sciences > Organic Chemistry|
|Date Deposited:||23 Mar 2006|
|Last Modified:||19 Sep 2010 04:24|
Actions (login required)