Saeed A. Fakhri, Behrooz H. Yousefi *
Department of Org. Chemistry, Faculty of Chemistry , Tabriz University, Tabriz, Iran
Phone: 0098 41 3348624, Fax: 0098 41 3340191, bhy@ark.tabrizu.ac.ir
 

ABSTRACT

8-Hydroxy-5,8,9,10-tetrahydro-6H-benzocycloocten-7-one 3, 5,6,9,10-tetrahydro-benzo-cyclooctene -7,8-dione 4 and 6,7,10,11-tetrahydro-benzocycloocta[b]quinoxaline 5 have been synthesised. The synthetic method involved modified acyloin cyclization of 3-[2-(2-ethoxycarbonyl-ethyl)-phenyl]-propionic acid ethyl ester 1 to 7,8-Bis-trimethylsilanyloxy-5,6,9,10-tetrahydro-benzocyclo-octene 2 followed by acid-catalyzed hydrolysis furnished the acyloin 3, and / or by oxidation with Jones reagent yielded to the ?-diketone 4. The corresponding quinoxaline 5 was prepared by the reaction of  4 ?-diketone with benzene-1,2-diamine in acetic acid. The structure and spectral behavior of these molecules have been elucidated with molecular mechanical and quantum mechanical methods.