3811-24-3Relevant academic research and scientific papers
Synthesis of plastoquinone derivatives with different structures of the side chain
Liu, Benli,Gu, Lianquan,Zhang, Jingling
, p. 104 - 110 (2007/10/02)
Two schemes for the synthesis of plastoquinone derivatives with ω-substituted alkyl side chains have been developed, based on radical alkylation of 2,3-dimethyl-1,4-benzoquinone with ω-substituted carboxylic and/or dicarboxylic acids in the presence of S2O82- and Ag+.In Scheme 1, radical alkylation of 2,3-dimethyl-1,4-benzoquinone with 11-bromoundecanoic acid, in the presence of (NH4)2S2O8 and AgNO3, gave 2,3-dimethyl-5-(10-bromodecyl)-1,4-benzoquinone, which, after hydration, gave 2,3-dimethyl-5-(10-hydroxydecyl)-1,4-benzoquinone.Esterification of 2,3-dimethyl-5-(10-hydroxydecyl)-1,4-benzoquinone with different acyl chlorides gave 2,3-dimethyl-5-(10-acyloxydecyl)-1,4-benzoquinone.In Scheme 2, radical alkylation of 2,3-dimethyl-1,4-benzoquinone with adipic acid, in the presence of K2S2O8 and AgNO3, gave 2,3-dimethyl-5-(4-carboxybutyl)-1,4-benzoquinone, which was converted to 2,3-dimethyl-5--1,4-benzoquinone by esterification with different alcohols in the presence of dicyclohexylcarbodiimide. 2,3-Dimethyl-5-(8-carboxyoctyl)-1,4-benzoquinone and 2,3-dimethyl-5--1,4-benzoquinone were similarly synthesized from 2,3-dimethyl-1,4-benzoquinone and sebacic acid.Plastoquinone derivatives having different kinds of double bonds in the side chain with and without a 6-methyl group were synthesized from 2,3,5-trimethyl-1,4-benzoquinone and 2,3-dimethyl-1,4-benzoquinone by successive reactions with (1) NaBH4; (2) KHSO4, different kinds of allylic alcohols; (3) Ag2O.The allylic alcohols were prepared from their corresponding aldehydes by reduction with NaBH4. 2,3,6-Trimethyl-1,4-benzoquinone by radical methylation with acetic acids in the presence of K2S2O8 + AgNO3.
Allylation of quinones bu allylic indium reagents
Araki, Shuki,Katsumura, Nobuhito,Butsugan, Yasuo
, p. 7 - 24 (2007/10/02)
Allylation of a variety of quinones by allylic indium sesquihalides was studied.Reactions of unsubstituted p-benzoquinone with allylindium, prenylindium, and geranylindium reagents gave, after oxidation with silver oxide, the corresponding allylated quinones in good yields.These reactions appear to proceed via 1,2-addition of the allylic indium reagents at the γ-carbon followed by sigmatropic rearrangement.Substituted quinones reacted with allylindium reagent giving excellent yields of allylquinols, whereas with prenylindium and geranylindium reagents, trisubstituted quinones gave diprenylcyclohexene-1,4-diones and 2,3-disubstituted quinones gave mixtures of prnylhydroquinones and diprenylcyclohexene-1,4-diones.In the prenylation of haloquinones, 1,2-addition, sigmatropic rearrangement, and elimination of indium(III) halide occurred in sequence yielding prenylquinones. 2-Hydroxy- and 2-methoxy-1,4-naphthoquinones gave α-addition products with prenylindium and cinnamylindium reagents.
