3-Aryltetronic Acids: Efficient Preparation and Use as Precursors for Vulpinic Acids
作者:Aurélie Mallinger、Thierry Le Gall、Charles Mioskowski
DOI:10.1021/jo802038z
日期:2009.2.6
3-Aryltetronic acids were prepared in one step by treatment of a mixture of methyl arylacetates and methyl hydroxyacetates with potassium tert-butoxide, via tandem transesterification/Dieckmann condensation. Several mushroom or lichen pigments, vulpinic acids, were synthesized from 3-(4-methoxyphenyl)tetronic acid in three steps involving the reaction of the corresponding dianion with an α-ketoester
通过串联酯交换反应/ Dieckmann缩合反应,用叔丁醇钾处理芳基乙酸甲酯和羟基乙酸甲酯的混合物,一步制得3-芳基酸。在三个步骤中,由3-(4-甲氧基苯基)tetronic酸合成了几种蘑菇或地衣颜料的硫化松香酸,这三个步骤涉及相应的二价阴离子与α-酮酸酯的反应以及所获得的叔醇的脱水成(E)的混合物-和(Z)-烯烃,它们在254nm的紫外线辐射下转化为天然(E)-异构体。樟脑酸,4,4'-二甲氧基硫代乙酸的合成,以及最近分离出的甲基3',5'-dichloro-4,4'-di- O的首次合成因此,以有效的方式获得了苹果酸-草酸甲酯。