80070-30-0Relevant articles and documents
Photochemistry of α-oxo oximes. Part 10. Photochemistry of three cyclic α-oxo oxime methyl ethers and their acyclic analogue at λ 254 nm
Buys, Theo S. V.,Cerfontain, Hans,Geenevasen, Jan A. J.,Stunnenberg, Frank
, p. 491 - 501 (2007/10/02)
The (E)- and (Z)-isomers of the 3,3,n,n-tetramethyl-2-(methoxyimino)-1-cycloalkanones (n=5 to 7) (3a-c) and their analogue (Z)-4-(methoxyimino)-2,2,5,5-tetramethyl-3-hexanone have been irridated at λ 254 nm in acetonitrile as solvent in order to study the influence of ring size on product formation.The dependence of product composition on irridation time revealed that the (E)-isomers of 3a-c undergo both E-Z isomerization and photodecomposition, whereas the (Z)-isomers undergo only Z-E isomerization.The primary step in photodecomposition is homolysis of the N-O bond.The observed products result from the various possible reactions of initially formed methoxy and cyclic iminyl radicals 17, cyanoacyl radicals 18 formed by ring opening of 17, cyanoalkyl radicals 19 formed from 18 by decarbonylation and cyclopentaniminyl radical 20b, formed by cyclization of the 5-cyano-2-hexyl radical 19b.Mechanisms for the formation of the various products are proposed and the relative importance of the various steps is discussed, also in relation to the results obtained using carbon tetrachloride as radical scavenger.Irridation of (Z)-4 at λ 254 nm leads to decomposition with formation of 2,2-dimethylpropanenitrile, methanol, isobutane and isobutene.
