Polymer-supported phosphonates. Olefins from aldehydes, ketones, and dioxolans by means of polymer-supported phosphonates

Abstract

Phosphonates substituted with electron-withdrawing groups (CN and CO₂Me) have been supported, by means of a neutralization reaction, on the macroreticular anion-exchange resin Amberlyst A-26. Treatment of carbonyl compounds with the polymer-bound phosphonate in various solvents gave olefins in high yields, at room temperature. Either batch or column techniques are employed, the latter offering the opportunity of a continuous procedure. The simultaneous use of the phosphonate resin and of an acidic one (Amberlyst 15 H) allowed the direct sequential hydrolysis and olefination of dioxolans.