Synthesis of new furan derivatives and 4-hydroxy aldehydes from 4-hydroxy 1-enol ethers

Starting from 4-hydroxy 1-enol ethers 3 different gamma-lactols 4 were successfully prepared by acidic hydrolysis. Subsequent oxidation of 4 with pyridinium chlorochromate (PCC) led to gamma-lactones 6 in good to excellent overall yields. Treatment of gamma-lactols 4 with silylated nucleophiles 7 in the presence of Lewis acids afforded substituted tetrahydrofuran derivatives 8 in good to excellent yields. Additionally, different functionalized aldehydes 12, 13, and 14 were prepared employing the TBS-protected enol ether 11 as precursor. All these transformations demonstrate the synthetic versatility of compounds 3.