Study of an unexpected rearrangement of the alpha-phenyl pyrane derivatives prepared via hetero-Diels-Alder reaction of acyclic vinyl allenes and aldehydes.
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.
Ruiz
Juan M
JM
Instituto Universitario de Bio-Orgánica Antonio González, Departamento de Química Orgánica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain.
Regás
David
D
Afonso
María M
MM
Palenzuela
J Antonio
JA
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
D000447:Aldehydes; D000466:Alkadienes; D001880:Boranes; D011714:Pyrans; C021274:boron trifluoride