Stereoselectivities of the Intramolecular Diels-Alder Reaction in the Azanona- and Azaditriene Series. Preparation of some Polyhydro-Isoindoles, Polyhydroisoquinolines, Decahydropyrido[2,1-A]Isoindo-Les and Decahydro-2H[-Pyrido[1,2-B]Isoquinolines

摘要

Substituted polyhydroisoindoles and polyhydroisoquinolines were prepared through ring-opening of 3-bromo-2,5-dimethylthiophene-1,1-dioxide (1) with amines 2 and 3 giving trienes 5 and 6, which could be cyclized in an intramolecular Diels-Alder reaction (IMDA). As examples the stereoselective preparation (92-99%) of decahydropoyrido[2,1-a]isoindoles (14 and 15) an decahydro-2H-pyrido[1,2-b]isoquinolines (19 and 20) in 60-63% via a TiCl_4 catalyzed IMDA reaction is shown.