Intramolecular Hetero-Diels-Alder Reaction of N-Arylimines. Applications to the Synthesis of Octahydroacridine Derivatives
نویسنده
چکیده
A new intramolecular Lewis acid catalyzed hetero-Diels-Alder reaction of N-arylimines 5 with nonactivated olefins tethered to the 2-azadiene system was developed in order to prepare 1,2,3,4,4a,9,9a,lO-octahydroacridine derivatives 6. Both reactivity and cis/ trans selectivity of 6 were mainly dependent on the substitution pattern in the 3-position of the cyclization precursor 5. The type of Lewis acid plays only a minor role in determination of the cis/trans ratio. The synthetic utility of this new cyclization was increased by performing it as a one-pot reaction (3 + 4 6). Both absolute configuration and preferred conformation were assigned by detailed NMR studies.
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