<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Venkatesan, K.</style></author><author><style face="normal" font="default" size="100%">Pujari, Suresh S.</style></author><author><style face="normal" font="default" size="100%">Lahoti, Rajgopal J.</style></author><author><style face="normal" font="default" size="100%">Srinivasan, K. V.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Efficient synthesis of 1,8-dioxo-octahydro-xanthene derivatives promoted by a room temperature ionic liquid at ambient conditions under ultrasound irradiation</style></title><secondary-title><style face="normal" font="default" size="100%">Ultrasonics Sonochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">aldehydes</style></keyword><keyword><style  face="normal" font="default" size="100%">ambient conditions</style></keyword><keyword><style  face="normal" font="default" size="100%">Bronsted acidity</style></keyword><keyword><style  face="normal" font="default" size="100%">dimedone</style></keyword><keyword><style  face="normal" font="default" size="100%">Ionic liquid</style></keyword><keyword><style  face="normal" font="default" size="100%">Ultrasound</style></keyword><keyword><style  face="normal" font="default" size="100%">Xanthenes</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">APR</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">4</style></number><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE BV</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">548-553</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The condensation reaction involving an aldehyde and diketone was efficiently promoted by the Ionic liquid, [Hbim]BF(4) (IL) as a reaction medium with methanol as co-solvent at ambient temperature under ultrasonic irradiation to afford the corresponding 1,8-dioxo-octahydroxantliene (xanthene) derivatives in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under ambient temperature without the requirement of ally added catalyst. The reaction times and yields are compared with p-TSA catalyzed synthesis of xanthenes under thermal conditions, which is also reported for the first time under our reaction conditions. (c) 2007 Elsevier B.V. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">4.456</style></custom4></record></records></xml>