- Discovery of highly potent analgesic activity of isopulegol-derived (2R,4aR,7R,8aR)-4,7-dimethyl-2-(thiophen-2-yl)octahydro-2H-chromen-4-ol
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A large set of chiral heterocyclic compounds with the octahydro-2H-chromene scaffold was first obtained by a reaction of (?)-isopulegol and (+)-neoisopulegol with furan-2-carbaldehyde, thiophene-2-carbaldehyde and their derivatives and isomers in the pres
- Nazimova, Ekaterina,Pavlova, Alla,Mikhalchenko, Oksana,Il’ina, Irina,Korchagina, Dina,Tolstikova, Tatyana,Volcho, Konstantin,Salakhutdinov, Nariman
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Read Online
- Method for preparation of L-menthone from R-citronellal
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The invention discloses a method for preparation of L-menthone from R-citronellal. In the presence of a Ru-Cu-MOF catalyst, R-citronellal is cyclized to prepare L-menthone, the reaction conditions aremild, the reaction enantioselectivity is 90%-99.5%, the conversion rate can reach 95%-99.9%, and the ee value of menthone can reach 90%-99.9%.
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Paragraph 0094; 0095
(2020/04/02)
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- Photocatalytic Annulation-Alkynyl Migration Strategy for Multiple Functionalization of Dual Unactivated Alkenes
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A novel photoredox catalysis for multiple functionalization of two different types of unactivated alkenes in a single operation was reported through a conceptually new mode of annulation-alkynyl migration. A wide array of cyclopentane carboxylates were sy
- Zhao, Qi,Hao, Wen-Juan,Shi, Hao-Nan,Xu, Ting,Tu, Shu-Jiang,Jiang, Bo
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supporting information
p. 9784 - 9789
(2019/12/24)
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- Chemoenzymatic Synthesis of the Intermediates in the Peppermint Monoterpenoid Biosynthetic Pathway
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A chemoenzymatic approach providing access to all four intermediates in the peppermint biosynthetic pathway between limonene and menthone/isomenthone, including noncommercially available intermediates (-)-trans-isopiperitenol (2), (-)-isopiperitenone (3), and (+)-cis-isopulegone (4), is described. Oxidation of (+)-isopulegol (13) followed by enolate selenation and oxidative elimination steps provides (-)-isopiperitenone (3). A chemical reduction and separation route from (3) provides both native (-)-trans-isopiperitenol (2) and isomer (-)-cis-isopiperitenol (18), while enzymatic conjugate reduction of (-)-isopiperitenone (3) with IPR [(-)-isopiperitenone reductase)] provides (+)-cis-isopulegone (4). This undergoes facile base-mediated chemical epimerization to (+)-pulegone (5), which is subsequently shown to be a substrate for NtDBR (Nicotiana tabacum double-bond reductase) to afford (-)-menthone (7) and (+)-isomenthone (8).
- Cheallaigh, Aisling Ní,Mansell, David J.,Toogood, Helen S.,Tait, Shirley,Lygidakis, Antonios,Scrutton, Nigel S.,Gardiner, John M.
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p. 1546 - 1552
(2018/08/04)
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- Grafted non-ordered niobium-silica materials: Versatile catalysts for the selective epoxidation of various unsaturated fine chemicals
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Two kinds of niobium(V)-silica catalysts for the selective epoxidation were synthesised by post-synthesis modification of non-ordered mesoporous silica supports, starting from niobocene dichloride via solvent-less organometallic precursor dry impregnation
- Tiozzo, Cristina,Bisio, Chiara,Carniato, Fabio,Guidotti, Matteo
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- 3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol: The importance of functional groups for antiparkinsonian activity
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Compounds with different sets of three of the four functional groups of (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol 1 possessing high antiparkinsonian activity were synthesized. The synthesized compounds were tested for the antiparkinsonian activity in vivo on a mouse model with MPTP neurotoxin. A pronounced antiparkinsonian effect of 1 can only be achieved if it contains all the four functional groups (two hydroxy groups and two double bonds). The 2-hydroxy group or the 3,4-double bond is not required for stimulating the exploratory activity of the animals.
- Ardashov, Oleg V.,Pavlova, Alla V.,Korchagina, Dina V.,Volcho, Konstantin P.,Tolstikova, Tat'yana G.,Salakhutdinov, Nariman F.
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p. 731 - 739
(2013/09/23)
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- Total synthesis and biological evaluation of (-)-9-deoxy-englerin a
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An effective total synthesis of (-)-9-deoxy-englerin (4), an analogue of the natural guaiane sesquiterpene englerin A (1), has been achieved. The synthesis features a transannular epoxide opening to construct the 5,7-fused ring system followed by transannular ether formation with mercury(II) trifluoroacetate.
- Ushakov, Dmitry B.,Navickas, Vaidotas,Strobele, Markus,Maichle-Moessmer, Caecilia,Sasse, Florenz,Maier, Martin E.
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scheme or table
p. 2090 - 2093
(2011/06/22)
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- Aerobic oxidation of monoterpenic alcohols catalyzed by ruthenium hydroxide supported on silica-coated magnetic nanoparticles
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Ruthenium hydroxide supported on silica-coated magnetic nanoparticles was shown to be an efficient heterogeneous catalyst for the liquid-phase oxidation of a wide range of alcohols using molecular oxygen as a sole oxidant in the absence of co-catalysts or additives. The material was prepared through the loading of the amino modified support with ruthenium(III) ions from an aqueous solution of ruthenium(III) chloride followed by treatment with sodium hydroxide to form ruthenium hydroxide species. Characterizations suggest that ruthenium hydroxide is highly dispersed on the support surface, with no ruthenium containing crystalline phases being detected. Various carbonylic monoterpenoids important for fragrance and pharmaceutical industries can be obtained in good to excellent yields starting from biomass-based monoterpenic alcohols, such as isoborneol, perillyl alcohol, carveol, and citronellol. The catalyst undergoes no metal leaching and can be easily recovered by the application of an external magnet and re-used.
- Costa, Vinicius V.,Jacinto, Marcos J.,Rossi, Liane M.,Landers, Richard,Gusevskaya, Elena V.
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experimental part
p. 209 - 214
(2011/09/19)
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- Enantioselective synthesis of three stereoisomers of 5,9- dimethylpentadecane, sex pheromone component of Leucoptera coffeella, from (-)-isopulegol
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The coffee leaf miner, Leucoptera coffeella, is an economically important pest of coffee trees in Brazil. It has been demonstrated that the main sex pheromone component of this species is 5,9-dimethylpentadecane, however the stereochemistry of the natural
- Moreira, Jardel A.,Correa, Arlene G.
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p. 3787 - 3795
(2007/10/03)
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- Polyfluorinated quaternary ammonium salts of polyoxometalate anions: Fluorous biphasic oxidation catalysis with and without fluorous solvents
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[Matrix presented] Polyfluorinated quaternary ammonium cations, [CF 3(CF2)7(CH2)3] 3CH3N+ (RFN+), were synthesized and used as countercations for the [WZnM2(H 2O)2(ZnW9O34)2] 12- (M = Mn(II), Zn(II)) polyoxometalate. The (RFN +)12[WZnM2(H20)2 (ZnW9O34)2] compounds were fluorous biphasic catalysts for alcohol and alkenol oxidation, and alkene epoxidation with aqueous hydrogen peroxide. Reaction protocols with or without a fluorous solvent were tested. The catalytic activity and selectivity was affected by both the hydrophobicity of the solvent and the substrate.
- Maayan, Galia,Fish, Richard H.,Neumann, Ronny
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p. 3547 - 3550
(2007/10/03)
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- Scope of enantioselective Palladium(II)-catalyzed aerobic alcohol oxidations with (-)-sparteine
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Evaluation of the substrate scope for Pd(II)/ (-)-sparteine catalyzed aerobic oxidative kinetic resolution of secondary alcohols is disclosed. An improved system is found with use of tert-butyl alcohol solvent in which benzylic and aliphatic alcohols as well as alcohols containing olefins are effectively oxidatively resolved. For substrates that successfully undergo oxidative kinetic resolution, krel values are generally between 10 and 20. Successful scale-up of various substrates to 10-mmol scale is described. Extension to oxidative desymmetrization of 1,3-meso-diols is successful with enantiomeric excesses ranging from 78 to 85%.
- Mandal, Sunil K.,Jensen, David R.,Pugsley, Jacob S.,Sigman, Matthew S.
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p. 4600 - 4603
(2007/10/03)
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- Biosynthesis of menthofuran in Mentha x piperita: Stereoselective and mechanistic studies
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Mentha x piperita shoot tips and first leaf pair were fed with aqueous solutions of [2H2]- and [2H2]/[18O]-labeled pulegone. The essential oil was analyzed by solid phase microextraction and enantioselective multidimensional gas chromatography/mass spectrometry. After feeding experiments with labeled pulegone racemate, both labeled (S)-menthofuran and (R)-menthofuran were detectable simultaneously together with genuine (R)- menthofuran. It could be shown that both labeled pulegone enantiomers are converted by Mentha x piperita to the corresponding labeled menthofuran enantiomers, favoring the labeled analogue of the nongenuine (S)-pulegone. The oxygen in menthofuran is introduced by enzymatic oxidation of pulegone, as concluded from feeding experiments with mixed labeled [2H2]/[18O]pulegone.
- Fuchs, Sabine,Zinn, Silvia,Beck, Thomas,Mosandl, Armin
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p. 4100 - 4105
(2007/10/03)
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- Epimerization in acid degradation products of artemisinin
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Treatment of artemisinin 1 with acid leads to either a cyclohexane dione degradation product 10, which is a useful intermediate for biosynthetic studies of artemisinin, or to a decalin system which has undergone epimerization 8. It is shown by NMR spectro
- Hui, Shi-Man,Ngo, Koon-Sin,Brown, Geoffrey D.
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p. 3435 - 3442
(2007/10/03)
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- Large-Scale Preparation of Pure (+)-(1S,2R,5S)-5-Methyl-2-(1-methyl-1-phenylethyl)cyclohexanol
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A procedure is described for the preparation of (S)-(-)pulegone, (-)-1, starting from (S)-(-)citronellol, (-)-6, in a preparative scale.Compound (-)-1 can easily be converted into (+)-(1S,2R,5S)-5-methyl-2-(1-methyl-1-phenylethyl)cyclohexanol: (+)-2 by a procedure described in literature, which was simplified essentially.Now (+)-2 is accessible in larger amounts and thus is available as an efficient chiral auxiliary in stoichiometric asymmetric syntheses.
- Buschmann, Helmut,Scharf, Hans-Dieter
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p. 827 - 830
(2007/10/02)
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The 4,8,8-trlmethyl bicyclo [5,1,0] octanones 1 and 2, potential precursors of guaianes, were prepared in chiral form, starting from readily available ketones : (-)-1 from (-)-isopulegone and (-)-2 from (-)-carone, making use of two regioselective ring en
- Baudouy, Rene,Gore, Jacques,Ruest, Luc
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p. 1099 - 1108
(2007/10/02)
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