A highly stereoselective transformation of carboxylic esters to trisubstituted olefins via cationic cyclopropyl–allyl rearrangement of sulfonates of cis-1,2-disubstituted cyclopropanols
作者:Dzmitry G. Kananovich、Alaksiej L. Hurski、Oleg G. Kulinkovich
DOI:10.1016/j.tetlet.2007.09.172
日期:2007.11
Methanesulfonates of readily available cis-1,2-disubstituted cyclopropanols on reaction with magnesium bromide in diethyl ether undergo cyclopropyl–allyl rearrangement to afford allyl bromides, with an (E)-trisubstituted double bond, as main products. The amount of the corresponding (Z)-isomers did not exceed 5% when the reaction was performed at 0 °C, and the major concomitant products were the regioisomeric