Benzene-free synthesis of hydroquinone.
Benzene-free synthesis of hydroquinone.
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DOI：
10.1021/ja016460p
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发表时间：
2001-10
影响因子：
15
通讯作者：
Ningqing Ran;D. Knop;K. Draths;J. W. Frost
中科院分区：
文献类型：
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作者：
Ningqing Ran;D. Knop;K. Draths;J. W. Frost
目前合成对苯二酚的所有路线都使用苯作为起始原料。现在已经详细阐述了从葡萄糖到氢醌的替代路线。苯是一种挥发性致癌物，来源于不可再生的化石燃料原料，而葡萄糖是非挥发性的，无毒的，来源于可再生植物多糖。首先利用微生物催化将葡萄糖转化为奎尼酸。奎尼酸然后被化学转化为氢醌。大肠杆菌QP1.1/pKD12.138在发酵罐控制条件下，以20%（mol/mol）的产率从葡萄糖合成49 g/L的奎尼酸。奎尼酸在澄清、脱色、无铵离子的发酵液中用NaOCl氧化脱羧，然后中间体3（R），5（R）-三羟基环己酮脱水，以87%的收率得到纯化的对苯二酚。奎尼酸在发酵液中加入化学计量的（NH（4））（2）Ce（SO（4））（3）和V（2）O（5）进行无卤氧化脱羧反应，得到对苯二酚，产率分别为91%和85%。并确定了奎尼酸与催化量的金属氧化剂进行氧化脱羧反应的适宜条件。以K2 S2 O 8为助氧化剂，Ag（3）PO（4）（相对奎尼酸为2mol%）催化合成对苯二酚，产率为74%。除了建立一个重要的化学结构单元的全新途径之外，微生物合成奎尼酸的氧化提供了一个例子，说明如何通过将化学催化与生物催化相结合来规避芳烃对微生物的毒性。
All current routes for the synthesis of hydroquinone utilize benzene as the starting material. An alternate route to hydroquinone has now been elaborated from glucose. While benzene is a volatile carcinogen derived from nonrenewable fossil fuel feedstocks, glucose is nonvolatile, nontoxic, and derived from renewable plant polysacharrides. Glucose is first converted into quinic acid using microbial catalysis. Quinic acid is then chemically converted into hydroquinone. Under fermentor-controlled conditions, Escherichia coli QP1.1/pKD12.138 synthesizes 49 g/L of quinic acid from glucose in 20% (mol/mol) yield. Oxidative decarboxylation of quinic acid in clarified, decolorized, ammonium ion-free fermentation broth with NaOCl and subsequent dehydration of the intermediate 3(R),5(R)-trihydroxycyclohexanone afforded purified hydroquinone in 87% yield. Halide-free, oxidative decarboxylation of quinic acid in fermentation broth with stoichiometric quantities of (NH(4))(2)Ce(SO(4))(3) and V(2)O(5) afforded hydroquinone in 91% and 85% yield, respectively. Conditions suitable for oxidative decarboxylation of quinic acid with catalytic amounts of metal oxidant were also identified. Ag(3)PO(4) at 2 mol % relative to quinic acid in fermentation broth catalyzed the formation of hydroquinone in 74% yield with K(2)S(2)O(8) serving as the cooxidant. Beyond establishing a fundamentally new route to an important chemical building block, oxidation of microbe-synthesized quinic acid provides an example of how the toxicity of aromatics toward microbes can be circumvented by interfacing chemical catalysis with biocatalysis.