Photochemical approach to functionalized benzobicyclo[3.2.1]octene structures via fused oxazoline derivatives from 4- and 5-(o-vinylstyryl)oxazoles

Šagud, Ivana; Božić, Simona; Marinić, Željko; Sindler-Kulyk, Marija (2014) Photochemical approach to functionalized benzobicyclo[3.2.1]octene structures via fused oxazoline derivatives from 4- and 5-(o-vinylstyryl)oxazoles. Beilstein Journal of Organic Chemistry, 10 . pp. 2222-2229. ISSN 1860-5397

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Abstract

Novel cis/trans-4- and cis/trans-5-(2-vinylstyryl)oxazoles have been synthesized by Wittig reactions from the diphosphonium salt of α, α’-o-xylene dibromide, formaldehyde and 4- and 5-oxazolecarbaldehydes, respectively. In contrast, trans-5-(2- vinylstyryl)oxazole has been synthesized by the van Leusen reaction from trans-3-(2-vinylphenyl)acrylaldehyde which is prepared from o-vinylbenzaldehyde and (formylmethylene)triphenylphosphorane. The 4- and 5-(2-vinylstyryl)oxazoles afford, by photochemical intramolecular cycloaddition, diverse fused oxazoline-benzobicyclo[3.2.1]octadienes, which are identified and characterized by spectroscopic methods. The photoproducts formed are relatively unstable and spontaneously or on silica gel undergo oxazoline ring opening followed by formation of formiato- or formamido-benzobicyclo[3.2.1]octenone derivatives. On irradiation of 4-(2-vinylstyryl)oxazole small quantities of electrocyclization product, 4-(1, 2-dihydronaphthalen-2-yl)oxazole, are isolated and spectroscopically characterized.

Item Type:

Article

Uncontrolled Keywords:

bicyclo[3.2.1]octane; intramolecular photocycloaddition; oxazole; styryl; vinyl

Subjects:

NATURAL SCIENCES > Chemistry

Divisions:

NMR Center

Projects:

Project title	Project leader	Project code	Project type
NMR Spectroscopy and Modelling of Bioactive Molecules (Spektroskopija NMR i modeliranje bioaktivnih molekula)-	Dejan Plavšić	098-0982929-2917	MZOS
Heteropolycycles, scaffolds to bioactive compounds. Synthesis and photochemistry (Heteropolicikli, strukturne osnove za bioaktivne spojeve. Sinteza i fotokemija)-	Irena Škorić	125-0982933-2926	MZOS

Depositing User:

Željko Marinić

Date Deposited:

02 Oct 2015 10:54

URI:

http://fulir.irb.hr/id/eprint/2140

DOI:

10.3762/bjoc.10.230