122800-92-4

Upstream product

• 36047-17-3 5,5-dimethyl-3-phenyl-2-cyclohexen-1-one 
• 6267-39-6 3-ethoxy-5,5-dimethyl-2-cyclohexen-1-one 
• 122800-84-4 2-hydroxy-4,4-dimethyl-6-phenylcyclohexa-2,5-diene-1-one 

Relevant academic research and scientific papers

Superoxide Anion Radical (O2)-radical Mediated Base-Catalyzed Autoxidation of Enones

Seventeen variously substituted cyclohex-2-en-1-ones were prepared and reacted with superoxide anion radical (O2-radical generated from KO2/18-crown-6) in inert nonpolar aprotic media at room temperature.The 4,4,6,6-tetrasubstituted cyclohexenones (1b,1c, and 1d) proved to be totally inert,while those cyclohexenones possessing available acidic α'- or γ-hydrogens underwent O2-radical mediated base-catalysed autoxidation (BCA) generating various products depending on the nature and location of the substituents.Thus, 4,4- and 5,5-disubstituted substrates(2b, 2c, 2e, 2f and 3b, 3d, 3f-3i, respectively) gave 2-hydroxycyclohexa-2,5-dien-1-ones (7) as the major product (>80percent yield) upon aqueous acid workup while the corresponding 2-methoxy analogues 8 are obtained when the reaction is quenched with CH3I. 2,3-Epoxycyclohexanones 13 and oxidative cleavage products 11 and 12 are formed in the case of the 6,6-disubstituted systems (4a-4c); these oxidation products are accompanied by dimers 14 when the substituent on 4 is CH3 or H.Epoxide 23 is the primary isolable product in the 3,4,4-trialkyl system (5d).As expected for BCA processes, similar results were observed when these reactions were mediated by KOH (at room temperature) or KOC(CH3)3 (at -40 deg C).In the case of 6,6-diphenylcyclohex-2-en-1-one (4c), however, tert-butoxide-mediated BCA at -40 deg C yielded cyclopentene hydroxy acid 15 in addition to epoxide 13.The saturated analogue of 4c, 18, yielded primarily the corresponding saturated hydroxy acid 19, as well as several other oxidation products (20-22) depending on the reaction conditions.The mechanism of these transformations is rationalized in terms of base-induced reactions and rearrangements of the initially formed keto hydroperoxides.

Superoxide Anion Radical (O2-anionradical) Mediated Base Catalyzed Autooxidation of α-Keto Enols

Eight 4,4-disubstituted 2-hydroxycyclohexa-2,5-dien-1-ones were prepared by the base-catalysed autooxidation (BCA) of the corresponding 4,4- or 5,5-disubstituted cyclohex-2-en-1-ones.Upon reaction with superoxide anion radical (O2-anionradical, generated from KO2/18-crown-6) in inert nonpolar aprotic media at room temperature, α-keto enols 3a-g undergo initial deprotonation of the enol hydrogen followed by BCA at C3 of the resulting enolate.Aqueous acid workup of the reaction mixture yields lactols 4, while methyl iodide quenching generates methoxy lactones 5.Lactols 4 can be readily converted to their acetoxy analogues 8, opened to aldehydo methyl esters 6, or reduced to the related lactones 7.The latter suggests a convenient one-pot synthesis of 2,3-unsaturated δ-valerolactones from the corresponding cyclohex-2-en-1-ones. 4,4-Diphenyl enol 3h, by contrast, resists BCA (whether mediated by O2-anionradical or t-C4H9O-anion) to the corresponding lactol yielding instead a variety of oxidative cleavage products 13-18. 2-Hydroxyspirodec-1-en-3-one (21) also underwent O2-anionradical-mediated BCA, yielding diacids 22 and 26 as well as lactol 30.The synthetic applications of these results are also discussed.