212073-06-8Relevant academic research and scientific papers
The use of (-)-8-phenylisoneomenthol and (-)-8-phenylmenthol in the enantioselective synthesis of 3-functionalized 2-azabicyclo[2.2.1]heptane derivatives via aza-Diels-Alder reaction
Cardoso do Vale, Maria Luísa,Rodríguez-Borges, José Enrique,Caama?o, Olga,Fernández, Franco,García-Mera, Xerardo
, p. 9475 - 9482 (2007/10/03)
The asymmetric aza-Diels-Alder reaction of the (1R)-8-phenylmenthyl or (1R)-8-phenylisoneomenthyl glyoxylate-derived N-benzylimine with cyclopentadiene resulted in the enantioselective synthesis of the corresponding pure [(1S,3-exo)-2-benzyl-2-azabicyclo[2.2.1]hept-5-ene]-3-carboxylates (80 or 69% yield, respectively). Reduction of these cycloadducts with LiAlH4 afforded pure (-)-[(1S,3-exo)-2-benzyl-2-azabicyclo[2.2.1]hept-5-en-3-yl]methanol. Furthermore, a reaction sequence based on Barbier-Wieland degradation of both (1S,3-exo)-adducts afforded pure (+)-(1R)-2-benzoyl-2-azabicyclo[2.2.1]heptan-3-one. In the course of the two transformation sequences referred, the chiral auxiliaries were recovered in a virtually quantitative way.
Enantioselective synthesis of 3-functionalized 2-azabicyclo[2.2.1]hept- 5-enes by hetero Diels-Alder addition to cyclopentadiene
Blanco, Jose M.,Caamano, Olga,Fernandez, Franco,Garcia-Mera, Xerardo,Lopez, Carmen,Rodriguez, Gonzalo,Rodriguez-Borges, Jose E.,Rodriguez-Hergueta, Antonio
, p. 5663 - 5666 (2007/10/03)
Diels-Alder cycloaddition of N-benzyl imine of (1R)-8-phenylmenthyl glyoxylate to cyclopentadiene gave the mixture of adducts 3a-d. Major diastereoisomer, the (1S,exo)-adduct (3a), was isolated in 57% yield and transformed in 74% overall yield into (+)-(1
