Soluble and polymer-supported 2- and 3-benzylated furans for the preparation of α,β-ethylenic carbonyl compounds

Soluble and polymer-supported 2- and 3-benzylated furans were subjected to a sequence involving a Diels-Alder reaction with α,β-acetylenic carbonyl compounds, a Michael addition, and a subsequent retro-Diels-Alder reaction to yield olefinic compounds. On solid support, this traceless strategy is advantageous since pure compounds were released in the thermal cycloreversion step. The fur-2-ylated resin allowed a highly diastereoselective synthesis.