Original scientific paper

Twofold Photochemical Dehydrocyclization Reaction of Substituted 2,5-Distyrylthiophenes and 2,5-Distyrylfurans

Miroslav Bajić ; Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, 41000 Zagreb, Croatia
Grace M. Karminski-Zamola ; Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, 41000 Zagreb, Croatia
Nikola Blažević ; Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, 41000 Zagreb, Croatia

Abstract

The photochemistry of 2,5-distyrylthiophenes and 2,5-distyrylfurans was investigated. Dinaphtho[2,l-b:l’,2’-d]thiophene derivatives 26, 27 and 28 and dinaphthol2,1-b: r,2’-d]furan derivative 30 were detected as products of twofold photochemical dehydrocyclization. Dinaphtho[2,l-b:r,2’-dJfuran derivative 31 was prepared by onefold photochemical dehydrocyclization reaction from styryl derivative of naphtho[2,l-b]furan 24, dinaphtho[2,l-b:l’,2’- d]furan derivative 32 was prepared by hydrolysis of dinaphtho[2,l-b:l’,2’- d]furan derivative 30. The presence of U-2-(2-carboxystyryl)naphtho[2,l- b]thiophene-5-methoxylate (23) or £-2-(2-carboxystyryt)naphtho[2,l-b)fuian- 5-methoxylate (24) was not recorded as the product of onefold photochemical dehydrocyclization reaction derived from 2,5-distyrylthiophene derivative 9 or 2,5-distyrylfuran derivative 10, but they were synthesized from 19 and 20 according to the schemes. The mechanism of the twofold photochemical dehydrocyclization reaction is discussed.

Keywords

Hrčak ID:

137141

URI

https://hrcak.srce.hr/137141

Publication date:

29.1.1993.

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