Reactions of diosphenol and 3,6-dimethyl-1,2-cyclohexanedione with iodine-copper(II) acetate in acetic acid-water (5:1) at 80 °C gave the respective 3-hydroxy-2,5-dialkyl-1,4-benzoquinone in 25–80% yields. 2-t-Butyl-5-methylcyclohexanone similarly gave the corresponding 3-hydroxy-1,4-benzoquinone in 66% yield.
A New Synthesis of 3-Hydroxy-2,5-dialkyl-1,4-benzoquinone from 3-Halo-3,6-dialkyl-1,2-cyclohexanedione Using Iodine–Copper(II) Acetate
作者:C. Akira Horiuchi、Yasuto Suzuki
DOI:10.1246/bcsj.62.2919
日期:1989.9
The reaction of 3-iodo-3,6-dialkyl-1,2-cyclohexanedione (2) with iodine–copper(II) acetate in acetic acid–water (5:1) at 80 °C gave the respective 3-hydroxy-2,5-dialkyl-1,4-benzoquinone in 38–80% yields. On the other hand, the reaction of 2 with copper(II) acetate in acetic acid–water (10:1) under refluxing afforded the respective 3,3′-dihydroxy 2,2′,5,5′-tetraalkyl-4,4′-diphenoquinone (5) in 41–85%
3-碘-3,6-二烷基-1,2-环己二酮 (2) 与碘-乙酸铜 (II) 在乙酸-水 (5:1) 中在 80 °C 下反应得到各自的 3-羟基- 2,5-二烷基-1,4-苯醌的产率为 38-80%。另一方面,2与乙酸铜(II)在乙酸-水(10:1)中回流反应得到各自的3,3'-二羟基2,2',5,5'-四烷基-4, 4'-二苯醌 (5) 的产率为 41–85%。在3-溴-3,6-二烷基衍生物(3)与乙酸铜(II)的情况下,得到二苯醌衍生物和3-羟基-2,5-二烷基-1,4-苯醌。
Photo-irradiation of α-halo carbonyl compounds: a novel synthesis of α-hydroxy- and α,α′-dihydroxyketones
The reaction of g.-halo ketones (alpha-iodocycloalkanones, alpha-bromocycloalkanones, alpha-iodo-beta-alkoxy esters, and alpha-iodoacyclic-ketones) with irradiation under a high-pressure mercury lamp gave the corresponding alpha-hydroxyketones in good yields. For alpha-bromoketones, it was found that alpha-hydroxylation does not occur. However, alpha-bromoketones were convened into a-hydroxyketones in the presence of KI. In the case of alpha,alpha(1)-diiodo ketones, alpha,alpha(1)-dihydroxyketones, which up to now have scarcely been reported, were obtained. This reaction affords a new, clean and convenient synthetic method for alpha-hydroxy- and alpha,alpha(1)-dihydroxyketones. (C) 2005 Elsevier Ltd. All rights reserved.
A novel synthesis of α-hydroxy- and α,α′-dihydroxyketone from α-iodo and α,α′-diiodo ketone using photoirradiation
A novel reaction of alpha-iodo ketone (alpha-iodocycloalkanone, alpha-iodo-beta-alkoxy ester, and alpha-iodoacyclicketone) with irradiation under a high-pressure mercury lamp gave the corresponding alpha-hydroxyketone in good yields. In the case of alpha,alpha'-diiodo ketone, alpha,alpha'-dihydroxyketone which little has been reported until now was obtained. This reaction affords a new, clean and convenient synthetic method for alpha-hydroxy- and alpha,alpha'-dihydroxyketone. (C) 2003 Elsevier Ltd. All rights reserved.