| Affiliation: | 1. Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. Carpio y Plan de Ayala, 11340 México, D.?F., Mexico, (phone: (+5255)5729‐6300/62411;2. fax: (+5255)5729‐6300/46211);3. Facultad de Estudios Superiores‐Cuautitlán, Universidad Nacional Autónoma de México, Campo 1, Cuautitlán Izcalli, 54740 Edo. de México, Mexico;4. Instituto de Investigaciones Quimicobiológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edif. B‐1, Ciudad Universitaria, Francisco J. Mujica S/N, 58066 Morelia, Mich., Mexico;5. Departamento de Química Orgánica, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón esq. Paseo Tollocan, 50120 Toluca, Edo. de México, Mexico;6. C. Eugene Bennett Department of Chemistry, West Virginia University, P.?O. Box 6045, Morgantown, West Virginia 26506‐6045, USA |
| Abstract: | The reactivity and selectivity of the the captodative olefins 1‐acylvinyl benzoates 1a – 1f and 3a as heterodienes in hetero‐Diels–Alder reactions in the presence of electron‐rich dienophiles is described. Heterodienes 1 undergo regioselective cycloaddition with the alkyl vinyl etherdienophiles 6a , b and 9 to give the corresponding dihydro‐2H‐pyrans 7, 8 , and 10 under thermal conditions. The reactivity of these cycloadditions depends, to a large extent, on the electronic demand of the substituent in the aroyloxy group of the heterodiene. Frontier‐molecular‐orbital (FMO; ab initio) and density‐functional‐theory (DFT) calculations of the ground and transition states account for the reactivity and regioselectivity observed in these processes. |
