Diversity-oriented synthesis of 1-hydroxy-2,4-benzodioates by regioselective [3+3] cyclocondensations of 1,3-bis(silyloxy)-1,3-butadienes with 3-alkoxy- and 3-silyloxy-2-alkoxycarbonyl-2-en-1-ones
作者:Mohanad Shkoor、Abdolmajid Riahi、Olumide Fatunsin、Ibrar Hussain、Mirza A. Yawer、Mathias Lubbe、Stefanie Reim、Helmut Reinke、Christine Fischer、Peter Langer
DOI:10.1039/b900542k
日期:——
1-Hydroxy-3,5-dimethyl-2,4-benzodioates (4-hydroxyisophthalates) were prepared by [3+3] cyclocondensation of 1,3-bis(silyloxy)-1,3-butadienes with 3-ethoxycarbonyl-4-trimethylsilyloxy-3-penten-2-one which is synthesized from (symmetrical) ethyl 2-acetylacetoacetate. The [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 3-alkoxy-2-alkoxycarbonyl-2-en-1-ones, readily available by reaction of β-ketoesters with trialkyl orthoformiates, provide a convenient and regioselective approach to a great variety of 3-substituted 1-hydroxy-2,4-benzodioates that are not readily available by other methods.
1-羟基-3,5-二甲基-2,4-苯二酸酯(4-羟基异苯甲酸酯)是通过1,3-二(硅氧基)-1,3-丁二烯与3-乙氧基carbonyl-4-三甲基硅氧基-3-戊烯-2-酮的[3+3]环缩合反应制备的,该3-乙氧基carbonyl-4-三甲基硅氧基-3-戊烯-2-酮是从(对称)乙基2-乙酰乙酸乙酯合成的。1,3-二(硅氧基)-1,3-丁二烯与3-烷氧基-2-烷氧基carbonyl-2-烯-1-酮的[3+3]环化反应,后者通过β-酮酯与三烷基甲酸醛的反应容易获得,提供了一种方便且区域选择性的途径,以合成多种不易通过其他方法获得的3-取代1-羟基-2,4-苯二酸酯。