Formation of enantiopure tricyclic compounds by intramolecular 1,3- dipolar cycloaddition of nitrones

Article abstract of DOI:10.1016/S0040-4020(98)00064-7

Nitrones 6 prepared from ester 5 underwent an intramolecular cycloaddition affording diastereomeric mixtures of tricyclic compounds 7A/B. These were separated to give the enantiopure compounds 7A and 7B. Starting from aminoalcohol 8 compounds 10A and 10B were formed via nitrones 9, Nitrone 9a yielded the transproduct 10aC in addition. X-ray analyses confirm the structure of TaB and 10aA. Catalytic hydrogenation of compounds 7A and 7B yielded the bicyclic c-aminoalcohols, which were tested as ligands in the enantioselective addition of diethylzinc to benzaldehyde.