engleski

VARIOUS PHOTOTRANSFORMATIONS OF NOVEL STYRYL-SUBSTITUTED FURO-BENZOBICYCLO[3.2.1]OCTADIENE DERIVATIVES

The photochemistry of styryl substituted monofuran derivatives has been thoroughly investigated [1] in order to prepare furan polycyclic structures, potentially biologically active compounds. The irradiation of the furan and benzofuran derivative 1 resulted in intramolecular cycloaddition and efficient formation of the bicyclo[3.2.1]octadiene structure 2. No intramolecular cycloaddition product was found upon irradiation of o-vinylstyryl derivative of naphtho[2, 1-b]furan 3 in which the furan ring is a part of the even more condensed system [2]. In order to prepare the naphthofuran derivative of benzo-bicyclo[3.2.1]octadiene 4, new methodology was successfully introduced starting with already previously obtained styryl derivative of furo-benzobicyclo[3.2.1]octadiene 5. On irradiation of vinyl derivative 5c instead of expected double bicyclic structure 6, as the main photoproduct, the phenanthrene derivative 7 was formed. The investigations were carried out also on the model compound 8 in order to see the substituent effect on the reaction course. The possible mechanism will be discussed. References [1] M. Šindler-Kulyk, L. Špoljarić ; Ž. Marinić, Heterocycles 1989, 27, 679. [2] I. Škorić, Ž. Marinić, M. Šindler-Kulyk, Heterocycles 2000, 53, 55.

phototransformations; photochemistry; bicyclo-octadiene derivatives; furans

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