ISSN:
0941-1216
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The photooxygenation of 4-methoxy-7-methyl-5 H-furo[3,2-g][1]benzopyran-5-one (Visnagin, 1) in methanol in absence and in presence of a sensitizer (methylene blue) has been studied, 6-Formyl-7-hydroxy-5-methoxy-2-methylchromone (4a), methyl 7-hydroxy-5-methoxy-2-methylchromone-6-carboxylate (4b) and 7-hydroxy-5-methoxy-2-methylchromone-6-carboxylic acid (4c) could be isolated and identified in each case. The formation can be interpreted in terms of intermediate production of a 1.2-dioxetane like 2.A comparative study on the ozonolysis of Visnagin (1) in ethyl acetate both in absence and in presence of dimethyl sulfide, was also undertaken. Ozone attacks 1 either at the furan ring (to give 4a, c) or at both the furan and γ-pyrone site (to afford 10). Possible reaction mechanisms are considered and the structures of the new products are based upon compatible and spectroscopic evidences.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19933350303
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