Deoxygenation of polyhydroxybenzenes: An alternative strategy for the benzene-free synthesis of aromatic chemicals
Deoxygenation of polyhydroxybenzenes: An alternative strategy for the benzene-free synthesis of aromatic chemicals
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DOI：
10.1021/ja0176346
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发表时间：
2002-05-29
影响因子：
15
通讯作者：
Frost, JW
中科院分区：
文献类型：
--
作者：
Hansen, CA;Frost, JW
在葡萄糖和芳香族化合物如连苯三酚、对苯二酚和间苯二酚之间建立了新的合成联系。该方法的核心是从1，2，3，4-四羟基苯、羟基氢醌和间苯三酚甲醚中除去一个氧原子，分别形成连苯三酚、氢醌和间苯二酚。脱氧是通过铑催化氢化的起始多羟基苯，然后酸催化脱水推定的二氢中间体。焦性没食子酸的合成包括将葡萄糖转化为肌醇、氧化肌醇-2-肌醇、脱水为1，2，3，4-四羟基苯和脱氧形成焦性没食子酸。焦性没食子酸肌醇的合成需要4步酶催化和2步化学反应。为了比较，从葡萄糖经由没食子酸中间体和莽草酸途径合成焦性没食子酸需要至少20个酶催化步骤。一种新的无苯合成对苯二酚的方法是将葡萄糖转化为2-脱氧-scyllo-肌醇，该肌醇脱水为羟基对苯二酚，随后脱氧形成对苯二酚。由2-脱氧鲨肌醇合成对苯二酚需要2个酶催化和2个化学步骤。相比之下，使用莽草酸途径和奎尼酸的中间体合成对苯二酚需要18个酶催化步骤和1个化学步骤。间苯三酚甲醚经三乙酸内酯甲基化、环化和区域选择性脱氧得到间苯二酚。鉴于从葡萄糖合成三乙酸内酯的能力，这构成了合成间苯二酚的第一条无苯路线。
New synthetic connections have been established between glucose and aromatic chemicals such as pyrogallol, hydroquinone, and resorcinol. The centerpiece of this approach is the removal of one oxygen atom from 1,2,3,4-tetrahydroxybenzene, hydroxyhydroquinone, and phloroglucinol methyl ether to form pyrogallol, hydroquinone, and resorcinol, respectively. Deoxygenations are accomplished by Rh-catalyzed hydrogenation of the starting polyhydroxybenzenes followed by acid-catalyzed dehydration of putative dihydro intermediates. Pyrogallol synthesis consists of converting glucose intomyo-inositol, oxidation tomyo-2-inosose, dehydration to 1,2,3,4-tetrahydroxybenzene, and deoxygenation to form pyrogallol. Synthesis of pyrogallol viamyo-2-inosose requires 4 enzyme-catalyzed and 2 chemical steps. For comparison, synthesis of pyrogallol from glucose via gallic acid intermediacy and the shikimate pathway requires at least 20 enzyme-catalyzed steps. A new benzene-free synthesis of hydroquinone employs conversion of glucose into 2-deoxy-scyllo-inosose, dehydration of this inosose to hydroxyhydroquinone, and subsequent deoxygenation to form hydroquinone. Synthesis of hydroquinone via 2-deoxy-scyllo-inosose requires 2 enzyme-catalyzed and 2 chemical steps. By contrast, synthesis of hydroquinone using the shikimate pathway and intermediacy of quinic acid requires 18 enzyme-catalyzed steps and 1 chemical step. Methylation of triacetic acid lactone, cyclization, and regioselective deoxygenation of phloroglucinol methyl ether affords resorcinol. Given the ability to synthesize triacetic acid lactone from glucose, this constitutes the first benzene-free route for the synthesis of resorcinol.