Synthesis of 4-Azidotetrahydropyrans via Prins Cyclization

Significance

The synthesis of all-cis 4-azidotetrahydropyrans 3 via the three-component coupling of aldehydes 1, homoallylic alcohols 2 and trimethylsilyl azide in the presence of phosphomolybdic acid (PMA) is described. The reaction is tolerant of a wide range of aldehydes bearing linear and branched aliphatic chains and electron-poor, -neutral and -rich aromatic groups. The acid-sensitive cinnamaldehyde was also found to participate well in the reaction. Furthermore, the coupling of substituted homoallylic alcohols was examined and found to proceed smoothly under the standard reaction conditions.