... Tetrahedron Letters. Volume 47, Issue 1, 2 January 2006, Pages 39–41. Cover image Cover image. Synthesis of substituted pyrano[3,2-c]pyridines via Diels–Alder reaction of 3-methylenepyridin-4-one. ... References and notes. 1; K. Faber, H. Stueckler, T. Kappe; J. Heterocycl. ...