Intramolecular hetero-Diels-Alder reaction of N-arylimines. Applications to the synthesis of octahydroacridine derivatives
作者:Sabine Laschat、Juergen Lauterwein
DOI:10.1021/jo00062a033
日期:1993.5
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,10-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.
Clean and atom-economic synthesis of octahydroacridines: application to essential oil of citronella
作者:Raquel G Jacob、Gelson Perin、Giancarlo V Botteselle、Eder J Lenardão
DOI:10.1016/s0040-4039(03)01749-0
日期:2003.9
A green and efficient method for the synthesis of octahydroacridine (OHA) has been developed by a simple one-pot hetero-Diels-Alder reaction starting from (+)-citronellal and N-arylamines in the presence of a solid supported catalyst (SiO2/ZnCl2), under MW irradiation and without any solvent. The method was used in the direct preparation of OHA from citronella oil in good yield. (C) 2003 Elsevier Ltd. All rights reserved.