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
Synthesis of β-Substituted Chalcones from Phenones via Conjugated Nucleophilic Substitution of Propargylic Alcohols
作者:Daniel Chapdelaine、Taoufik Halima
DOI:10.1055/s-0031-1290677
日期:2012.7
Phenones can be efficiently transformed into beta-substituted chalcones in a two-step process. First, propargylic alcohols were obtained by addition of ethoxyacetylene anion to aromatic ketones. Activation of the propargylic alcohols using a catalytic amount of acid in the presence of an electron-rich aromatic ketone affords the title enones in moderate to good yields.