A diastereoselective synthesis of 4-azidotetrahydropyrans via the Prins-cyclization

A three component coupling of aldehydes, homoallylic alcohols and sodium azide is achieved in the presence of trifluoroacetic acid in dichloromethane to produce 4-azidotetrahydropyran derivatives in high yields with all cis-selectivity. The use of trifluoroacetic acid makes this procedure simple and cost-effective.