ChemInform Abstract: Exploration of C5—C6‐Unsubstituted 1, 4‐Dihydropyridines for the Construction of exo‐Hexahydro‐1H‐chromeno[3, 4‐h][1, 6]naphthyridine‐3‐carboxylates Using a Stereoselective Povarov Reaction. Issue 6 (21st January 2016)