52900-79-5Relevant academic research and scientific papers
One-step synthesis of furan-2,5-dicarboxylic acid from furan-2-carboxylic acid using carbon dioxide
Fischer, Robert,Fiserova, Maria
, p. 405 - 412 (2014/01/23)
A short and effective method for preparation and isolation of furan-2,5-dicarboxylic acid has been developed. Furan-2,5-dicarboxylic acid was prepared directly from furan-2-carboxylic acid in one step under strong basic conditions using carbon dioxide. This method allows to obtain the product with high added value, furan-2,5-dicarboxylic acid, from natural sources such as hemicelluloses containing pentoses. ARKAT-USA, Inc.
The scent of bacteria: Headspace analysis for the discovery of natural products
Citron, Christian A.,Rabe, Patrick,Dickschat, Jeroen S.
supporting information, p. 1765 - 1776 (2013/01/15)
Volatile compounds released by 50 bacterial strains, 45 of them actinobacteria in addition to three chloroflexi and two myxobacteria, have been collected by use of a closed-loop stripping apparatus, and the obtained headspace extracts have been analyzed by GC-MS. Excluding terpenes that have recently been published elsewhere, 254 compounds from all kinds of compound classes have been identified. For unambiguous compound identification several reference compounds have been synthesized. Among the detected volatiles 12 new natural products have been found, in addition to mellein, which was released by Saccharopolyspora erythraea. The iterative PKS for this compound has recently been identified by in vitro experiments, but mellein production in S. erythraea has never been reported before. These examples demonstrate that headspace analysis is an important tool for the discovery of natural products that may be overlooked using conventional techniques. The method is also useful for feeding experiments with isotopically labeled precursors and was applied to investigate the biosynthesis of the unusual nitrogen compound 1-nitro-2-methylpropane, which arises from valine. Furthermore, several streptomycetes emitted compounds that were previously recognized as insect pheromones, thus questioning if bacterial symbionts are involved in insect communication.
Synthese, Thermolyse und Photolyse substituierter 3,4-Epoxy-cycloalkene
Eberbach, Wolfgang,Carre, Jean Claude
, p. 1027 - 1047 (2007/10/02)
The substituted epoxy-cycloalkenes 5 - 7 are transformed thermally at 200 - 250 deg C into the benzene derivatives 10, 15, and 18 after initial C/O-bond cleavage of the oxirane ring.At temperatures higher than 300 deg C (short time pyrolysis) 6 and 7 give, in addition to the aromatic compounds 15/18, the furans 16 and 19, respectively.On photochemical excitation 5 - 7 react with C/C-ring opening to the annelated 2,3-dihydrofurans 11, 17, and 20, respectively.The epoxycycloheptene 8 undergoes analogous ring expansion leading to 21 on electronic as well as thermal activation (ca. 80percent yield).Whereas 21 does not form any defined product up to 380 deg C, and the monosubstituted bicyclus 11 suffers fragmentation affording methyl 3-furancarboxylate (12) and ethylene, both dihydrofurans 17 and 20 are quantitatively converted back into the epoxy-cycloalkenes 6 and 7, respectively, at temperatures below 200 deg C; the cycloreversion reaction affording 16/19 competes only above 300 deg C.The cyclic dipoles of type IV, assumed to occur as intermediates during the 2,3-dihydrofuran-vinyloxirane isomerisations 17 . 6/20 . 7, can be trapped with dimethyl acetylenedicarboxylate or N-phenylmaleimide at significantly lower temperature (150/120 deg C) to give the 1:1-cycloadducts 38 - 40.However, because no such products could be obtained in case of the photoreactions of 5 - 8, a concerted -C-migration has to be considered as a mechanistic alternative of the light-induced formation of 11, 17, 20, and 21.
