Cyclohexadienones from

The catalytic systems described thus far have the advantage of preventing large quantities of gem-chlotinated cyclohexadienones from forming. This type of by-product can, however, always be eliminated with reduciag agents (25,31,32) or acids (33). 

ZINCKE - SUHL Cyclohexadienone synthesis Synthesis of cyclohexadienones from phenols by Fnedel Crafts alkylafion... 

The reaction can be used to prepare hexaethyl-2,4-cyclo-hexadienone, m.p. 44-45°, in 82% yield from hexaethylbenzene and 3,4,6,6-tetramethyl-2,4-cyclohexadienone from durene in over 80% yield. 

Fig. 2.34. Formation of cyclohexadienones from 2,2-disubstituted vinylcarbene complexes.

Kuniyoshi M, Oshiro N, Miono T, Higa T (2003) Halogenated Monoterpenes Having a Cyclohexadienone from the Red Alga Portieria hornemannii. J Chin Chem Soc 50 167... 

For the sake of completeness, it should be mentioned that the formation of hydroperoxycyclohexadienone CXIV by oxidation of XXIV was described34, 164 l66 as well as of the mixture of 2-hydroperoxy-2,4,6-tri-tert-butyl-3,5-cyclohexadienone with 4-hydroperoxy-2,4,6-tri-tert-butyl-2,5-cyclohexadienone from 2,4,6-tri-tert-butylphenol166 167 by oxidation with the triplet ground state oxygen in alkaline medium. This process proceeds by another mechanism than that described in Scheme 13. 

Hydrogen peroxide sulfuric acid acetic anhydride 2,4-Cyclohexadienones from benzene ring... 

N-Carbalkoxyethylation s. 14, 397 N-Pyridylethylation s. 11, 389 4-Nitro-2,5-cyclohexadienones from phenols s. 11, 390... 

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