title: Study of an unexpected rearrangement of the alpha-phenyl pyrane derivatives prepared via hetero-Diels-Alder reaction of acyclic vinyl allenes and aldehydes.
abstract: The Lewis acid catalyzed hetero-Diels-Alder reaction between acyclic vinyl allenes and aldehydes as heterodienophiles was studied. This reaction allows for the preparation of pyrane derivatives in good yields, high facial and regioselectivity and moderate endo/exo ratio. When benzaldehyde was used as the heterodienophile, rearranged products were obtained depending on the reaction conditions. DFT calculations were used to study the rearrangement, concluding that it is a highly selective ionic process, driven by the stability of the rearranged products.
authors.affiliation: Instituto Universitario de Bio-Orgánica Antonio González, Departamento de Química Orgánica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Ruiz
authors.forename: David
authors.initials: D
authors.lastname: Regás
authors.forename: María M
authors.initials: MM
authors.lastname: Afonso
authors.forename: J Antonio
authors.initials: JA
authors.lastname: Palenzuela
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000466:Alkadienes / Q000737:chemistry*; D001880:Boranes / Q000737:chemistry; D002384:Catalysis; D003198:Computer Simulation; D008956:Models, Chemical; D015394:Molecular Structure; D011714:Pyrans / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000447:Aldehydes; D000466:Alkadienes; D001880:Boranes; D011714:Pyrans; C021274:boron trifluoride