The reaction of alkyl-substituted sec-ethoxyalkynyl acetates with water catalyzed by Hg(OTf)(2) afforded alpha,beta-unsaturated esters in excellent yield with high catalytic turnover up to 1000 times under very mild reaction conditions with virtually complete E-selectivity, superior even to that of the HWE reaction.
The Meyer-Schuster Rearrangement of Ethoxyalkynyl Carbinols
作者:Gregory Dudley、Susana Lopez、Douglas Engel
DOI:10.1055/s-2007-973885
日期:2007.4
combination of electron-rich alkoxyacetylenes and cationic gold catalysts provides excellent reactivity for the Meyer-Schusterrearrangement under mild conditions. Optimization of the reaction conditions with respect to stereoselectivity and investigations into the scope and mechanism of the rearrangement of secondary ethoxyalkynyl carbinols (y-ethoxy-substituted propargyl alcohols) to α,β-unsaturated esters
Lewis acid-catalyzed Meyer–Schuster reactions: methodology for the olefination of aldehydes and ketones
作者:Douglas A. Engel、Susana S. Lopez、Gregory B. Dudley
DOI:10.1016/j.tet.2008.02.030
日期:2008.7
In principle, the most efficient and atom-economical means of converting an aldehyde or ketone into the homologated α,β-unsaturatedester is through addition/rearrangement sequences involving acetylenic π-bonds (Scheme 1). Implementation of such a strategy for the synthesis of α,β-unsaturatedesters is presented: addition of ethoxyacetylene followed by scandium(III) triflate-catalyzed Meyer–Schuster