- Synthesis of Ethyl-4-ethoxy Pentanoate by Reductive Etherification of Ethyl Levulinate in Ethanol on Pd/SiO2-C Catalysts
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The synthesis of biomass-derived ethers to be used as biofuels or biofuel additives has attracted much attention. Following the recently reported synthesis of etherified ester ethyl-4-ethoxy pentanoate (EEP) from γ-valerolactone (GVL) in ethanol catalyzed by H-beta zeolite, an alternative route to prepare EEP in high yield has been developed by reductive etherification of ethyl levulinate (EL) in ethanol at 140 °C under 0.5 MPa H2 with a silica-modified Pd/C catalyst. The ether production likely follows a tandem acetalization–hydrogenolysis process with ethyl-4,4-diethoxy pentanoate (EDEP) as the intermediate. The acetalization step can be favored by introducing acidic materials, such as SiO2–carbon or beta zeolite, as a cocatalyst. The combination of the Pd/SiO2-C and beta zeolite mixture leads to 100 % EL conversion and 93 % EEP selectivity under optimized reaction conditions. For the first time, the standard molar combustion enthalpy of as-prepared EEP is measured by using a static oxygen bomb, and the value of which is determined to be about ?5658 kJ mol?1, which is much larger than that of GVL (?2650 kJ mol?1).
- Cui, Qianqian,Long, Yinshuang,Wang, Yun,Wu, Haihong,Guan, Yejun,Wu, Peng
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p. 3796 - 3802
(2018/10/24)
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- Introduction of a carboxyl group through an acetal as a new route to carboxylic acid derivatives of sugars
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A new class of carboxylic acid derivatives of sugars is described. Acetalation of mono- and disaccharides with a functionalized vinylic ether or a diethoxybutanoate afforded mono- and diacetals bearing an ester group. Their saponification led to the corresponding carboxylic acid acetals in which the length of the acetal side chain can be modulated. Copyright (C) 1999 Elsevier Science Ltd.
- Carbonnel, Sylvie,Fayet, Catherine,Gelas, Jacques
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