Original scientific paper

Synthesis and Photochemistry of Styryl Substituted Annelated Furan Derivatives. IV. Concentration Directed Intra- and/or Intermolecular [2+2] Cycloaddition

Irena Škorić ; Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
Željko Marinić ; The Rugjer Bošković Institute, P. O. Box 180, 10002 Zagreb, Croatia
Marija Šindler-Kulyk ; Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia

Abstract

New cyclobutane derivatives have been synthesized by intermolecular photochemical [2+2] ethene-ethene »head-to-head« (9a,b) and »head-to-tail« (10a,b–11a,b) as well as [2+2] ethenefuran (12a,b) cycloaddition from 2-[2-(2-vinylphenyl)ethenyl]benzo[b]furan (2a) and 2-[2-(2-methylphenyl)ethenyl]benzo[b]furan (2b), respectively. All compounds were isolated and characterized by spectroscopic methods. Under the benzene solution irradiation of 5 × 10-1 mol dm-3 concentration and higher, 2-[2-(2-vinylphenyl)ethenyl]benzo[b]furan (2a) gave only dimeric products (9a–12a). At the 1 × 10-1 mol dm-3 concentration, a mixture of dimers (9a–12a) and 7,12-dihydro-7,12-methano-6H-benzo[4,5]cyclohepta[1,2-b]benzofuran (5) was formed in a ratio 2:1.

Keywords

synthesis; photochemistry; furan; cyclobutane; benzo[b]furan; cycloaddition

Hrčak ID:

102660

URI

https://hrcak.srce.hr/102660

Publication date:

31.5.2004.

Visits: 1.299 *