Proline-mediated enantioselective construction of tetrahydropyridines via a cascade Mannich-Type/Intramolecular Cyclization reaction

A highly diastereo- and enantioselective synthesis of 2,3-disubstituted tetrahydropyridines was accomplished via a proline-mediated cascade Mannich-type/intramolecular cyclization reaction from preformed N-PMP (p-methoxyphenyl) aldimines and inexpensive aqueous tetrahydro-2Hpyran-2,6-diol.