- Novel access to cyclohexane-1,4-diones and 1,4-hydroquinones via radical 1,2-acyl rearrangement on 2-(halomethyl)cyclopentane-1,3-diones using cobaloxime-mediated electroreduction or tributyltin hydride
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A new preparative access to synthetically useful cyclohexane-1,4-diones 2 and their oxidized analogues, hydroquinones 3, with the option of introducing alkyl and aryl substituents, was developed by radical 1,2-acyl rearrangement on 2-(halomethyl)cyclopentane-1,3-diones 1, accessible from 1,2-bis(trimethylsiloxy)cyclobutene and α-bromo ketone dimethyl acetals. The electroreduction of monoacetals of 1 in the presence of cobaloxime as a catalyst afforded the cyclohexane-1,4-dione monoacetals in good yields. The Bu3SnH-reduction of 2-aryl 1 under refluxing in benzene effected the rearrangement, affording 2, and when the reaction was prolonged, aromatization to 3 proceeded in moderate yields.
- Kawafuchi, Hiroyuki,Inokuchi, Tsutomu
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p. 2051 - 2054
(2007/10/03)
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- SUBSTITUTED 7,7',8,8'-TETRACYANOQUINODIMETHANES. I. METHODS OF SYNTHESIS OF SUBSTITUTED 7,7',8,8'-TETRACYANOQUINODIMETHANES
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The synthesis of 2-methyl-, 2,5-dimethyl-, and 2-isopropyl-7,7'-8,8'-tetracyanoquinodimethanes was realized from 2-methyl-, 2,5-dimethyl-, and 2-isopropyl-1,4-cyclohexanediones.These cyclic diketones are obtained with good yields by the Birch reduction of 2-chloromethyl-, 2,5-dichloromethyl-, and 2-isopropyl-1,4-dimethoxybenzenes.
- Russkikh, V. S.,Abashev, G. G.
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p. 742 - 745
(2007/10/02)
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