Diastereoselective synthesis of tetrahydrofurans via Palladium(0)-catalyzed [3 + 2] cycloaddition of vinylcyclopropanes and aldehydes.

Palladium(0)-catalyzed cycloadditions of malonate-derived vinylcyclopropane 1 and aldehydes to afford 2,5-cis disubstituted tetrahydrofuran derivatives are described. Pd loadings as low as 0.5 mol % were effective in catalyzing the transformation with high yields and diastereoselectivities. Electron-poor aldehydes work best, suggesting that a mechanism involving an initial aldol reaction may be operative.