Enantioselective synthesis of 3-functionalized 2-azabicyclo[2.2.1]hept- 5-enes by hetero Diels-Alder addition to cyclopentadiene

Article abstract of DOI:10.1016/S0040-4039(98)01102-2

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