Autor: |
Gavrilova, G., Aleshkin, A., Nikanorov, V., Krut'ko, D., Rozenberg, V., Reutov, O. |
Zdroj: |
Russian Chemical Bulletin; 1995, Vol. 44 Issue 3, p502-506, 5p |
Abstrakt: |
A novel method for the synthesis of the oxime of 4-methyl-2,4,6-cycloheptatrien-1-one (Eschenmoser's oxime) is proposed. The method involves redox enlargement of the ring of 4-dibromomethyl-4-methyl-2,5-cyclohexadien-1-one oxime through the action of Ni(PPh) in DMF (in the presence of Zn). The product is formed as a mixture of syn- and anti-forms readily interconverting in solutions. A similar reaction of 4-methyl-4-trichloromethyl-2,5-cyclohexadien-1-one oxime afforded the dimer of a gem-α-centered semiquinoid carbene (1,2-bis-(1-methyl-4-oxyimino-2,5-cyclohexadienyl)-1,2-dichloroethylene), together with syn- and anti-isomers of 4-chloro-5-methyl-2,4,6-cycloheptatrien-1-one oxime, which are readily separable but also quickly interconverting in solutions. For the latter compounds, the completeH NMR assignment of the stereoisomeric structures has been carried out. [ABSTRACT FROM AUTHOR] |
Databáze: |
Complementary Index |
Externí odkaz: |
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