- Transition-Metal-Free Access to Heteroaromatic-Fused 4-Tetralones by the Oxidative Ring Expansion of the Cyclobutanol Moiety
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Advances in the transition-metal-free cyclobutanol ring expansion to 4-tetralones under N-bromosuccinimide mediation are described. We have expanded the scope of this ring expansion methodology and investigated the effect substituents on the aromatic ring, and the cyclobutanol moiety, have on the outcome of the reaction. Limitations with certain substituents on the cyclobutanol moiety are also described. Further experimental evidence to support our mechanistic understanding is disclosed, and we now preclude the suggested involvement of a primary radical for this transformation.
- Natho, Philipp,Allen, Lewis A. T.,White, Andrew J. P.,Parsons, Philip J.
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p. 9611 - 9626
(2019/08/16)
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- 1H-pyrrole-2,4-dicarbonyl-derivatives and their use as flavoring agents
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The present invention primarily relates to 1H-pyrrole-2,4-dicarbonyl-derivatives of Formula (I) wherein R1, R2, R3, Z. Z' and J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) or of a mixture of compounds of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- Imidazo[1,2-a]pyridine-ylmethyl-derivatives and their use as flavoring agents
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The present invention primarily relates to imidazo[1,2-a]pyridine-ylmethyl-derivatives of Formula (I) wherein R1, R2, X, W e J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- UNIQUE HALOGEN-INDUCED CYCLIZATIONS, REAGENTS THEREFOR, AND COMPOUNDS PRODUCED THEREBY
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This disclosure is related to halonium compounds useful for cyclization of polyenes, alkenoic acids, and alkenyl alkyl ethers, and halogenation of aromatic compounds. The synthesis of such halonium compounds, compounds made using such halonium compounds, and synthesis of natural compounds, including decalins, using the halonium compounds is also disclosed. A representative halonium compound of the disclosure is: Formula (I).
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Page/Page column 128
(2012/04/04)
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- A general strategy for the stereocontrolled preparation of diverse 8- and 9-membered Laurencia -type bromoethers
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A unique procedure to effect a ring-expanding bromoetherification process is described, wherein tetrahydrofurans and tetrahydropyrans are smoothly transformed into 8- and 9-membered bromoethers in a regio- and stereocontrolled manner through the use of BDSB (bromodiethylsulfonium bromopentachloroantimonate). These products resemble the cores of the Laurencia C15 acetogenins. In light of the generality and effectiveness of the approach, this work provides a unique strategy for their laboratory preparation and may implicate a possible biosynthesis pathway.
- Snyder, Scott A.,Treitler, Daniel S.,Brucks, Alexandria P.,Sattler, Wesley
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supporting information; experimental part
p. 15898 - 15901
(2011/11/13)
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- Tandem Pd(II)-catalyzed vinyl ether exchange-claisen rearrangement as a facile approach to γ,δ-unsaturated aldehydes
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(Chemical Equation Presented) A sequential allyl vinyl ether formation-Claisen rearrangement process catalyzed by a palladium(II)- phenanthroline complex is reported. The effects of allylic alcohol structure, type of vinylating agent, and palladium catalysts are discussed. This method provides a convenient approach to γ,δ unsaturated aldehydes under mild conditions that avoid the use of toxic Hg(II) catalysts. The new methodology has been successfully demonstrated on the kilogram scale.
- Wei, Xudong,Lorenz, Jon C.,Kapadia, Suresh,Saha, Anjan,Haddad, Nizar,Busacca, Carl A.,Senanayake, Chris H.
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p. 4250 - 4253
(2008/02/04)
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- Intramolecular cyclopropanation of unsaturated terminal epoxides
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Efficient lithium amide-induced intramolecular cyclopropanation of bishomoallylic and trishomoallylic epoxides is described. The methodology is used in an asymmetric synthesis of sabina ketone. Copyright
- Hodgson, David M.,Chung, Ying Kit,Paris, Jean-Marc
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p. 8664 - 8665
(2007/10/03)
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- Synthesis of (E)-6-Nonen-1-ol, a Sex Pheromone of Male Fruit Fly Ceratitis capitata Wiedemann
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(E)-6-Nonen-1-ol (I) has been synthesised starting from propenal.Grignard reaction of ethylmagnesium bromide on propenal gives the allylic alcohol (II) which on mercuric acetate catalysed trans-etherification with ethyl vinyl ether yields the allyl vinyl ether (III).Claisen migration of III provides (E)-4-hepten-1-al (VI) which is smoothly reduced with LAH to the alcohol (V).Conversion of V into the corresponding mesylate (Va), followed by alkylation with ethyl malonate furnishes the diester (VI) which when decarbethoxylated with NaCl/DMSO yields ethyl (E)-6-nonenoate (VII).LAH reduction of VII results in the formation of the title compound (I).
- Vig, O. P.,Sharma, M. L.,Gakhar, Madhu,Malik, Neera
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p. 356 - 357
(2007/10/02)
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