- Regiospecific Synthesis of Quinizarin and Naphthazarin Derivatives by Cycloaddition
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The diene (E)-1,1,4-trimethoxybuta-1,3-diene underwent regiospecific cycloaddition to derivatives of 2(3)-chloro-1,4-naphthoquinone.The resulting adducts were aromatized to give 1,4-dioxygenated anthraquinones.The latter were obtained as derivatives of quinizarin dimethyl ether or of quinizarin monomethyl ether depending on the conditions of aromatization.Cycloaddition of the diene to non-halogenated naphthoquinones proceeded similarly, orientation being controlled by substituents in the benzenoid ring.Analogous reaction of the diene with benzoquinones gave 5,8-dioxygenated naphthoquinones (naphthazarins), generally in limited yield.The procedure has been applied to synthesis of the mould metabolites helminthosporin and cynodontin
- Cameron, Donald W.,Feutrill, Geoffrey I.,McKay, Peter G.
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p. 2095 - 2109
(2007/10/02)
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- REGIOSPECIFIC SYNTHESIS OF QUINIZARIN DERIVATIVES BY CYCLOADDITION
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Cycloaddition of (E)-1,1,4-trimethoxy-1,3-butadiene (1) to naphthoquinones affords regiospecific syntheses of derivatives of 1,4-dihydroxyanthraquinone including the mould metabolites helminthosporin (21) and cynodontin (22).
- Cameron, Donald W.,Feutrill, Geoffrey I.,McKay, Peter G.
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p. 701 - 702
(2007/10/02)
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