- CONDENSATION OF 2-(1-ETHOXYVINYL)OXIRANES WITH SODIOMALONIC ESTER AND DECARBOXYLATION OF THE REACTION PRODUCTS OBTAINED
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γ-(1-Ethoxyvinyl)- and β-(1-ethoxyvinyl)-α-ethoxycarbonyl-γ-butyrolactones were obtained by the reaction of 2-(1-ethoxyvinyl)oxiranes with sodiomalonic ester.Decarboxylation of the γ-(1-ethoxyvinyl)-α-ethoxycarbonyl-γ-butyrolactones in DMSO leads to γ-(1-ethoxyvinyl)-γ-butyrolactones, the hydrolysis of which gives γ-acetyl-γ-butyrolactones.Ethyl trans-3-acetyl-3-pentenoate was obtained by decarboxylation of γ-methyl-3-(1-ethoxyvinyl)-α-ethoxycarbonyl-γ-butyrolactone in DMSO.
- Martishonok, V. V.,Grinkevich, O. A.,Biba, V. I.,Bubel, O. N.
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- A VERSATILE AND CONCISE ROUTE TO FUNCTIONALLY SUBSTITUTED γ-BUTYROLACTONES AND SPIRO-γ-BUTIROLACTONES (LACTONE ANNELATION)
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A novel route to the synthesis of functionally substituted γ-butyrolactones and spiro-γ-butyrolactones, from six-membered cyclic enol-esters, is described.
- Mandal, Arun K.,Jawalkar, D. G.
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- Iodine(III)-Mediated Contraction of 3,4-Dihydropyranones: Access to Polysubstituted γ-Butyrolactones
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Functionalized γ-butyrolactones are privileged structures in the field of medicinal chemistry; they are found in numerous natural products and synthetic compounds with diverse biological activities. The oxidative ring contraction of 3,4-dihydropyran-2-one derivatives represents a promising yet underappreciated strategy to access these compounds. To the best of our knowledge, very few examples of this strategy have been reported, with limited investigation of the influence of stereogenic centers on the starting dihydropyranones. We investigated the iodine(III)-mediated contraction of a representative set of dihydropyranone derivatives. The method gives rapid access to functionalized γ-butyrolactones in good yields. The reaction scope was investigated, and the method was found to support various levels of substituents, even enabling access to sterically congested quaternary centers. The stereoselectivity was investigated using chiral substrates and a chiral iodine(III) reagent.
- Dagenais, Robin,Lussier, Tommy,Legault, Claude Y.
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p. 5290 - 5294
(2019/09/03)
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- Calcium iodide catalyzed photooxidative oxylactonization of oxocarboxylic acids using molecular oxygen as terminal oxidant
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We developed aerobic photooxidative oxylactonization of oxocarboxylic acids catalyzed by calcium iodide using molecular oxygen as the terminal oxidant under photo irradiation.
- Tada, Norihiro,Ishigami, Takafumi,Cui, Lei,Ban, Kazunori,Miura, Tsuyoshi,Itoh, Akichika
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supporting information
p. 256 - 258
(2013/02/23)
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- Facile aerobic photooxidative oxylactonization of oxocarboxylic acids in fluorous solvents
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We developed efficient aerobic photooxidative oxylactonizations of oxocarboxylic acids promoted by trifluoroacetic anhydride with molecular oxygen as the terminal oxidant in the fluorous solvent FC-72.
- Tada, Norihiro,Cui, Lei,Ishigami, Takafumi,Ban, Kazunori,Miura, Tsuyoshi,Uno, Bunji,Itoh, Akichika
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supporting information
p. 3007 - 3009,3
(2020/09/16)
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- In situ generated (Hypo)iodite catalysts for the direct α-oxyacylation of carbonyl compounds with carboxylic acids
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It′s the iodine: The intra- and intermolecular title reaction is catalyzed by an in situ generated ammonium (hypo)iodite species. Either H 2O2 or tert-butyl hydroperoxide (TBHP) can be used as an environmentally benign oxidant and a wide range of substrates react to give the corresponding α-acyloxycarbonyl compounds in good to excellent yields.
- Uyanik, Muhammet,Suzuki, Daisuke,Yasui, Takeshi,Ishihara, Kazuaki
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supporting information; experimental part
p. 5331 - 5334
(2011/07/08)
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- Oxidative rearrangement of 2-alkoxy-3,4-dihydro-2H-pyrans: stereocontrolled synthesis of 4,5-cis-disubstituted tetrahydrofuranones including whisky and cognac lactones and crobarbatic acid
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Oxidation of 2-alkoxy-3,4-dihydro-2H-pyrans 3 with dimethyldioxirane or MTO/urea-H2O2 followed by Jones oxidation leads to rearrangement and stereocontrolled formation of 4,5-cis-disubstituted tetrahydrofuranones. The method is applied to the synthesis of the whisky lactone 9, cognac lactone 10 and crobarbatic acid 17.
- Armstrong, Alan,Ashraff, Cassim,Chung, Hunsuk,Murtagh, Lorraine
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experimental part
p. 4490 - 4504
(2009/10/09)
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- Compound having effect of promoting neuron differentiation
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A novel cystacycline derivative which has an excellent effect of promoting the differentiation of neurons and is useful as a remedy for central nervous system disorders, a remedy for peripheral nerve disorders, etc.
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- Allene epoxidation: Synthesis of functionalized lactones by the DMDO oxidation of allenic acids
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A series of allenic carboxylic acids has been converted to functionalized lactones by oxidation-cyclization promoted by dimethyldioxirane. These transformations are rationalized by the involvement of unisolated allene oxide and spirodioxide intermediates. The structures of the starting allenic acids and the reaction conditions determine which of these two intermediate species serves as the source of the isolated products. The use of prepared solutions of the oxidant generally proceed via spirodioxides; whereas in situ reactions normally give products derived from the allene oxides. When products are formed directly from allene oxides, keto lactones are formed. The corresponding spirodioxide intermediates give lactones with appropriately situated α-hydroxyketone moieties. An understanding of the regiochemistry of the epoxidations and the subsequent cyclizations of the reactive intermediates is developed, as are methods for the manipulation of the experimental conditions to favor the desired products.
- Crandall, Jack K,Rambo, Elisa
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p. 7027 - 7036
(2007/10/03)
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- Studies toward the Syntheses of Functionally Substituted γ-Butyrolactones and Spiro-γ-butyrolactones and Their Reaction with Strong Acids: A Novel Route to α-Pyrones
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A general strategy for the conversion of 5-keto carboxylic acids, 6 (via their enol-lactones 7), to a variety of γ-lactones, 8a-c, and spiro-γ-lactones, 8d-g, is described.Lactones 8b and 8d,e may be further converted into the corresponding α-pyrones, 17b and 17d,e, respectively, in the presence of strong acids.
- Mandal, A.K.,Jawalkar, D.G.
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p. 2364 - 2369
(2007/10/02)
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