<?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%">Ramana, C. V.</style></author><author><style face="normal" font="default" size="100%">Induvadana, Boddeti</style></author><author><style face="normal" font="default" size="100%">Srinivas, Burgula</style></author><author><style face="normal" font="default" size="100%">Yadagiri, Kommagalla</style></author><author><style face="normal" font="default" size="100%">Deshmukh, Madhusudhan N.</style></author><author><style face="normal" font="default" size="100%">Gonnade, Rajesh G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Influence of electronic factors on pd-mediated cycloisomerization: a systematic investigation of competitive 6-exo-dig versus 7-endo-dig cyclizations of sugar alkynols</style></title><secondary-title><style face="normal" font="default" size="100%">Tetrahedron</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Alkynol cycloisomerization</style></keyword><keyword><style  face="normal" font="default" size="100%">Bridged bicyclic ketal</style></keyword><keyword><style  face="normal" font="default" size="100%">Palladium</style></keyword><keyword><style  face="normal" font="default" size="100%">Sonogashira coupling</style></keyword><keyword><style  face="normal" font="default" size="100%">Sugar alkynol</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">NOV</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">47</style></number><publisher><style face="normal" font="default" size="100%">PERGAMON-ELSEVIER SCIENCE LTD</style></publisher><pub-location><style face="normal" font="default" size="100%">THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND</style></pub-location><volume><style face="normal" font="default" size="100%">65</style></volume><pages><style face="normal" font="default" size="100%">9819-9832</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Pd-mediated cycloisomerization of 3-C-propargyl-ribo- and allofuranose derivatives was investigated in detail to understand the influence of electronic factors on the regioselectivity (6-exo- vs 7-endo) of alkynol cycloisomerization leading either to a six- or seven-membered ring. In general, the 6-exo-dig mode of cyclization is facile and is independent of electronic factors. With some of the alkynols, a regioselective (7-endo?) hydration of the alkyne unit was observed and this has been attributed to the participation of C(3)-OH. When the C(3)-OH was protected as its benzyl ether, cycloisomerization of these alkynols occurred exclusively in a 6-exo-dig mode resulting in the corresponding [3.2.1]-bicyclic ketals. Additional control experiments conducted were in support of the participation of C(3)-OH in regioselective alkyne hydration. (C) 2009 Elsevier Ltd. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">47</style></issue><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">&lt;p&gt;3.011&lt;/p&gt;</style></custom4></record></records></xml>