- The Photochemistry of Aliphatic and Alicyclic α,β-Unsaturated Nitro Compounds. A Study of Double Bond Cleavage Following Intramolecular Cyclization and Nitro-Nitrite Rearrangement
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The light-induced intramolecular cyclization of α,β-unsaturated nitro compounds leading to double bond cleavage, which had previously been detected in a small number of β-nitrostyrenes and α-nitrostilbenes, has been shown to occur in a range of aliphatic and alicyclic α,β-unsaturated nitro compounds.At room temperature the reaction competes to a significant extent with the well known nitro-nitrite rearrangement in the irradiation of 1-nitro-2-phenylcyclohexene (2), 1-methyl-2-nitrocyclohexene (6), 1-methyl-2-nitrocycloheptene (11), 2-methyl-3-nitrobut-2-ene (23)and 2-nitro-3-phenylbut-2-ene (24), while it was the only reaction detected in the case of 1-methyl-2-nitrocyclooctene (12) and 1-nitrocyclooctene (19).No evidence for the cleavage reaction was found with 1-methyl-2-nitrocyclopentene (10), 1-nitrocyclohexene (17), 1-nitrocycloheptene (18) and 3-nitropent-2-ene (25).The nitrile oxides produced in the double bond cleavage reaction were trapped in a cycloaddition with methyl acrylate, yielding 3-substituted methyl 4,5-dihydroisoxazole-5-carboxylates.Irradiations of 1-methyl-2-nitrocyclohexene (6) and 1-methyl-2-nitrocycloheptene (11) in refluxing benzene afforded only the bridged ring isoxazolines (30) and (31) respectively.Syntheses of a number of nitro-olefins are also reported.
- Grant, Richard D.,Pinhey, John T.
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p. 1231 - 1244
(2007/10/02)
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