Reactions of dicarbanion equivalents generated from complexation of 1,3-dienes on Ti(II) moiety
作者:Johann Baraut、Arnaud Perrier、Virginie Comte、Philippe Richard、Pierre Le Gendre、Claude Moïse
DOI:10.1016/j.tetlet.2006.09.077
日期:2006.11
Conjugated dienes are able to react as 1,2- or 1,4-dicarbanions by coordination on Ti(II) moiety. These two possibilities are exemplified in this letter with isoprene, myrcene and several aldehydes to give 1,4- and 1,6-diols. When allowed to react with esters at room temperature, the titanium-diene complexes lead to cyclopentenol derivatives. Surprisingly, when this reaction is performed at lower temperature (-40 degrees C), allylic ketones are formed with high regio and diastereoselectivities. (c) 2006 Elsevier Ltd. All rights reserved.