Three-component, one-pot diastereoselective synthesis of 4-amidotetrahydropyrans via the Prins–Ritter reaction sequence

Three-component coupling of carbonyl compounds, homoallylic alcohols, and nitriles has been achieved using 20 mol % of phosphomolybdic acid (PMA) at ambient temperature via the Prins–Ritter sequence to furnish 4-amidotetrahydropyrans in high yields with all cis selectivity. Spirocyclic-4-amidotetrahydropyrans are obtained using cyclic ketones.