15790-94-0

Enol ethers are formed by radical decarboxylation of α-alkoxy β-phenylthio acids via the corresponding Barton esters. The phenylthio acids were usually made by the known regioselective reaction of α,β-epoxy acids with PhSH in the presence of InCl3, followed by O-alkylation of the resulting alcohol. In one case, thiol addition to an α,β-unsaturated ethoxymethyl ester was used.

A highly practical and step-economic α,β-dehydrogenation of carboxylic acids via enediolates is reported through the use of allyl-palladium catalysis. Dianions underwent smooth dehydrogenation when generated using Zn(TMP)2?2 LiCl as a base in the presence of excess ZnCl2, thus avoiding the typical decarboxylation pathway of these substrates. Direct access to 2-enoic acids allows derivatization by numerous approaches.

PROBLEM TO BE SOLVED: To provide a manufacturing method which can get α,β-unsaturated carboxylic acid at a high yield by liquid phase oxidation of α,β-unsaturated aldehyde by oxygen or air with a handy metal catalyst under a mild reaction condition. SOLUTION: Preferably under a presence of organic solvent, α,β-unsaturated carboxylic acid is manufactured by oxidation of α,β-unsaturated aldehydes and oxygen or air under a presence of an iron salt catalyst and a catalyst of alkali metal salt of carboxylic acid. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT

GC-MS and GC-FTIR were complementarily applied to identify oxidation compounds formed under frying conditions in methyl oleate and linoleate heated at 180 °C. The study was focused on the compounds that originated through hydroperoxide scission that remain attached to the glyceridic backbone in fats and oils and form part of non-volatile molecules. Twenty-one short-chain esterified compounds, consisting of 8 aldehydes, 3 methyl ketones, 4 primary alcohols, 5 alkanes and 1 furan, were identified. In addition, twenty non-esterified volatile compounds, consisting of alcohols, aldehydes and acids, were also identified as major non-esterified components. Furanoid compounds of 18 carbon atoms formed by a different route were also identified in this study. Overall, the composition of the small fraction originated from hydroperoxide scission provides a clear idea of the complexity of the new compounds formed during thermoxidation and frying.

The present invention relates to a process for the preparation of dicarboxylic acids or dicarboxylic acid esters comprising the following process steps: A1 provision of at least the following reactants: a1 - a first aliphatic compound having 5 to 40 carbon atoms with in each case at least one functional group of the general formula (I) and (II), wherein R1 is a saturated or unsaturated aliphatic group having 2 to 20, preferably 4 to 16 and particularly preferably 6 to 12 carbon atoms and R2 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1, 2 or 3 carbon atoms formula (I) and (II) and a2 at least one further aliphatic compound which differs from the first aliphatic compound, chosen from the group consisting of a2a a compound of the general formula (III) in which n is chosen from 1, 2, 3, 4 and 5; a2b a compound of the general formula (IV) in which R3 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1, 2 or 3 carbon atoms and R4 and R5 independently of each other are a saturated alkylene group having 1 to 14 carbon atoms, preferably having 1 to 10 carbon atoms and very particularly preferably 1 to 5 carbon atoms; A2 provision of at least one organometallic catalyst based on ruthenium; A3 bringing into contact of the reactants and the catalyst to obtain a product mixture and the catalyst; A4 separating off of the catalyst; A5 optionally division of the product mixture into products Pi, i being a natural number, and the reactants which remain; the process being a metathesis reaction, and the dicarboxylic acid obtainable therefrom and the dicarboxylic acid ester obtainable therefrom, a process for the preparation of a polymer and the polymer obtainable by this process.

A combination of regioselective room-temperature/ambient-pressure hydroformylation (transitionmetal catalysis) and decarboxylative Knoevenagel reactions (organocatalysis) allowed for the development of an efficient, one-pot C3 homologation of terminal alkenes to (E)-α,β-unsaturated acids and esters, (E)-β,γ-unsaturated acids, (E)-α-cyano acrylic acids, and α,β-unsaturated nitriles. All reactions proceed under mild conditions, tolerate a variety of functional groups, and furnish unsaturated carbonyl compounds in good yields and with excellent regioand stereocontrol. Further, an iterative C2 homologation of (E)-α,β-unsaturated carboxylic acids is possible through a combination of decarboxylative hydroformylation employing a supramolecular catalyst followed by decarboxylative Knoevenagel condensation with an organocatalyst.

Combining the regioselective room temperature/ambient pressure hydroformylation and a modification of the Doebner-Knoevenagel reaction allowed for the development of an efficient, one-pot procedure for the synthesis of (E)-α,β-unsaturated carboxylic acids. The reaction proceeds under mild conditions, tolerates a variety of functional groups and gives (E)-α,β-unsaturated carboxylic acids in good yields and with excellent regio-and stereocontrol. The practicability of this process has been demonstrated by a short protecting group-free synthesis of the queen honeybee pheromones 9-ODA[( E)-9-oxodec-2-enoic acid] and 9-HDA[( E)-9-hydroxydec-2-enoic acid].

Reactions of NaHFe(CO)4/RX or [HFe3(CO)11]- reagents with alkynes lead to the formation of the corresponding α,β-unsaturated carboxylic acids and/or the cyclobutenediones. The reagent generated in situ using the NaHFe(CO)4/CH3I combination in THF, on reaction with alkynes followed by CuCl2·2H2O oxidation, gives the corresponding cyclobutenediones (27-42%) and α,β-unsaturated carboxylic acids (10-22%), whereas the reagent generated using CH2Cl2 in place of CH3I leads to α,β-unsaturated carboxylic acids (37-60%) and their derivatives (35-55%) at 25°C. The same reagent system in the presence of acetic acid (4 equiv) yields the corresponding cyclobutenedione (33%). The reaction using Me3SiCl gives the corresponding α,β-unsaturated carboxylic acids (45-54%) at 25°C and the corresponding cyclobutenediones (51-63%) at 60°C. Interestingly, the reaction of the [HFe3(CO)11]- species generated using Fe(CO)5/NaBH4/CH3COOH, with alkynes at 25°C, followed by CuCl2·2H2O oxidation gives the corresponding cyclobutenediones (60-73%). The possible intermediates and pathways for the formation of α,β-unsaturated carboxylic acids and cyclobutenediones are discussed.