ISSN:
0009-2940
Keywords:
Naphth[2,3-d]-1,2,3-oxadiazole
;
2,3-Naphthoquinone diazide
;
Wolff rearrangement, photochemical
;
Naphth[2,3-b]oxirene
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Photolysis of Naphth[2,3-d]-1,2,3-oxadiazole - A Contribution to the Oxirene ProblemThe photolysis of [9a-13C]naphth[2,3-d]-1,2,3-oxadiazole ([9a-13C]14) in methanol, water, and cyclohexane is studied. In the protic solvents, the Wolff rearrangement products 2-(methoxycarbonyl)indene ([13C=O]16) and 2-indenecarboxylic acid ([13C=O]23) exclusively labelled at the carbonyl carbon are obtained. Furthermore, the photolysis of [9a-13C]14 in methanol yields [2-13C]-2-naphthol (19) as hydrogen abstraction product. The photolytic decomposition of 14 in cyclohexane affords 2-(2-naphthoxycarbonyl)indene (25) and 1-cyclohexyl-2-(2-naphthoxycarbonyl)indene (26). The formation of 25 is explained by nucleophilic addition of 2-naphthol (19) to the intermediate ketene 21. 2-Naphthol (19) is generated in situ by hydrogen abstraction from cyclohexane. The cyclohexyl radicals, thereby obtained, convert 25 to 26. Similar photolysis of [9a-13C]14 affords [13C—O—13C=O]25 and [13C—O—13C=O]26 labelled at the carbonyl carbon and C-2 of the naphthalene ring. Thus, independent of the nature of the solvent (methanol, water, cyclohexane), no labelling distribution is found in the photolysis products of [9a-13C]14. This excludes the participation of naphth-[2,3-b]oxirene (17) as reactive intermediate.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19941270315
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