- Ene-Reductase Catalyzed Regio- and Stereoselective 1,4-Mono-Reduction of Pseudoionone to Geranylacetone
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The regio- and stereoselective mono-reduction of a particular C=C bond of conjugated C=C double bonds is a very challenging task. Here the regio- and stereoselective 1,4-reduction of pseudoionone, an α,β,γ,δ-bisunsaturated ketone, was demonstrated to give geranylacetone, an industrially relevant molecule. OYE1 from Saccharomyces pastorianus was identified as the most suitable biocatalyst for this reaction. Elevated substrate concentrations of up to 200 mM were tolerated allowing still to reach excellent conversions (>99 % and 80 % for 100 or 200 mM pseudoionone concentration, respectively). Interestingly, the organic cosolvent often required for substrate solubilization in aqueous buffer can be avoided for pseudoionone when using permeabilized E. coli cells containing the overexpressed enzyme instead of purified enzyme, reaching still >99 % conversion at 100 mM (19.2 g/L) substrate concentration. Performing this reaction at a 0.5 g scale allowed to run the reaction to completion (>99 %) and pure product was isolated with 80 % yield. Additionally, the bis-unsaturated ketone 6-methyl-3,5-heptadien-2-one was transformed under similar conditions giving the floral compound sulcatone with excellent conversion (97 %) and 77 % isolated yield. Finally, the stereoselective reduction of the (E,E)- over the (E,Z)-pseudoionone isomer was enabled by the ene-reductase from Zymomonas mobilis (NCR). Thus, both (E)-geranylacetone and (E,Z)-pseudoionone were obtained with isomeric excess above 60 %.
- Breuer, Michael,Ditrich, Klaus,Glueck, Silvia M.,Kroutil, Wolfgang,Oroz-Guinea, Isabel,Schachtschabel, Doreen,Weingarten, Melanie,Winkler, Christoph K.
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- Synthesis method and method for synthesizing plant alcohol, isoplant alcohol and geranyl geraniol by using intermediate farnesylacetone (by machine translation)
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The invention relates to a synthesis method of intermediate farnesyl acetone and a method for synthesizing vitamin E, vitamin K1, vitamin K2 side chain isovegetable alcohol, plant alcohol and geranyl geraniol by using farnesyl acetone, and concretely relates to hydrogenation of 5 - farnesyl -2 - acetone and farnesyl acetone through three Grignard reaction to obtain plant ketone. The farnesyl acetone reacts with the vinyl chloride Grignard reagent to obtain geranyl linalool, the aromatic leaf-based geraniol is rearranged under acid catalysis, or farnesyl acetone is directly reacted with the hydroxyl-protected 2 - chloroethanol Grignard reagent to obtain geraniol. The plant alcohol is reacted with the vinyl chloride Grignard reagent to obtain the plant alcohol, and the plant alcohol is directly reacted with the hydroxyl-protected 2 - chloroethanol Grignard reagent to obtain the plant alcohol. The method has the advantages of cheap and easily available starting materials, short synthetic process steps, low product cost and the like. (by machine translation)
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Paragraph 0061; 0072; 0080-0081
(2020/07/21)
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- Sesquiterpene Cyclizations inside the Hexameric Resorcinarene Capsule: Total Synthesis of δ-Selinene and Mechanistic Studies
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The synthesis of terpene natural products remains a challenging task due to the enormous structural diversity in this class of compounds. Synthetic catalysts are unable to reproduce the tail-to-head terpene cyclization of cyclase enzymes, which create this diversity from just a few simple linear terpene substrates. Recently, supramolecular structures have emerged as promising enzyme mimetics. In the present study, the hexameric resorcinarene capsule was utilized as an artificial cyclase to catalyze the cyclization of sesquiterpenes. With the cyclization reaction as the key step, the first total synthesis of the sesquiterpene natural product δ-selinene was achieved. This represents the first total synthesis of a sesquiterpene natural product that is based on the cyclization of a linear terpene precursor inside a supramolecular catalyst. To elucidate the reaction mechanism, detailed kinetic studies and kinetic isotope measurements were performed. Surprisingly, the obtained kinetic data indicated that a rate-limiting encapsulation step is operational in the cyclization of sesquiterpenes.
- Zhang, Qi,Tiefenbacher, Konrad
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p. 12688 - 12695
(2019/08/12)
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- Chemoenzymatic Synthesis of the Antifungal Compound (–)-Pestynol by a Convergent, Sonogashira Construction of the Central Yne-Diene
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A total synthesis of the fungal-derived natural product pestynol is reported via a convergent chemoenzymatic approach from the readily available precursors geranyl bromide, ethyl acetoacetate, trimethylsilylacetylene, and bromobenzene. Synthetic (–)-pestynol proved to be identical in all respects to the natural material, allowing confirmation of the structure including absolute stereochemistry.
- Borra, Suresh,Kumar, Manoj,McNulty, James,Baidilov, Daler,Hudlicky, Tomas
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supporting information
p. 77 - 79
(2018/11/23)
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- Total syntheses of parthenolide and its analogues with macrocyclic stereocontrol
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The first total synthesis of parthenolide (1) is described. The key feature of this synthesis is the formation of a 10-membered carbocylic ring by a macrocyclic stereocontrolled Barbier reaction, followed by a photoinduced Z/E isomerization. The biological evaluation of a small library of parthenolide analogues (19, 33, and 34) disclosed a preliminary structure-activity relationship (SAR). The results revealed that the C1, C10 double bond configuration of parthenolide has little or no effect on the activity, and the C6 and C7 configurations of the lactone ring have a moderate impact on the activities against some cancer cell lines.
- Long, Jing,Zhang, Shan-Feng,Wang, Pan-Pan,Zhang, Xue-Mei,Yang, Zhong-Jin,Zhang, Quan,Chen, Yue
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supporting information
p. 7098 - 7112
(2014/11/08)
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- Design, synthesis and anticancer activity evaluation of diazepinomicin derivatives
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A series of diazepinomicin derivatives were synthesized and evaluated in vitro for their growth inhibitory activity against the human carcinoma cell lines. The results indicated the anticancer selectivity of this kind of compounds. Based on the results, preliminary structure-activity relationships were discussed.
- Yu, Yongguo,Wu, Jianbo,Lei, Fan,Chen, Lei,Wan, Weili,Hai, Li,Guan, Mei,Wu, Yong
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p. 369 - 373
(2013/07/26)
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- Synthetic studies towards stachybotrin C
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The preparation of racemic des-hydroxy stachybotrin C is described. Different approaches have been studied. Observations made in the course of the synthesis show the efficiency of the intermolecular cyclization between the diethyl acetal 19 and phenol 12 leading to the benzopyran moiety 17. Georg Thieme Verlag KG · Stuttgart · New York.
- Tumma, Naresh,Jacolot, Maiwenn,Jean, Mickael,Chandrasekhar, Srivari,Van De Weghe, Pierre
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p. 2919 - 2922
(2013/02/22)
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- Control of the regio- and diastereoselectivity for the preparation of highly functionalized terpenic cyclopentanes through radical cyclization
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The titanocene-mediated cyclization of suitably functionalized acyclic C10 epoxy-polyprenes leads, with moderate stereoselectivity, to high yields of functionalized terpenic cyclopentanes with three contiguous stereogenic centers. These highly functionalized cyclopentanes are useful intermediates for the synthesis of several natural compounds that include this interesting subunit in their structure. Both the regioselectivity of the process leading to cyclopentanes and the stereoselectivity of the cyclization could be controlled by using malonyl derivatives or α,β-unsaturated nitriles as radical acceptors. The titanocene-mediated cyclization of suitably functionalized acyclic C10 epoxy-polyprenes proceeds with acceptable stereochemical control and excellent yields. The process takes place through 5-exo-trig ring closures and gives cyclopentanes with three contiguous stereogenic centers with peripheral functional groups that are suitable for constructing structurally complex natural products. Copyright
- Arteaga, Jesus F.,Dieguez, Horacio R.,Gonzalez-Delgado, Jose A.,Quilez Del Moral, Jose F.,Barrero, Alejandro F.
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supporting information; experimental part
p. 5002 - 5011
(2011/11/06)
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- A strategy for position-selective epoxidation of polyprenols
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An effective strategy has been developed for the efficient site-selective epoxidation of poylolefinic isoprenoid alcohols, based on the use of an internal control element for intramolecular reaction. The approach is illustrated by application to a series of polyisoprenoid alcohols (polyprenols) at substrate concentration of 0.5 mM. With polyprenol substrates having the hydroxyl function at one terminus, the internal epoxidation can be directed at the double bond of the polyprenol, which is either four or five away from the terminal hydroxyprenyl subunit.
- Gnanadesikan, Vijay,Corey
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supporting information; experimental part
p. 8089 - 8093
(2009/02/01)
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- Process for the preparation of unsaturated 4,5-allene ketones, 3,5-diene ketones and the corresponding saturated ketones
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Process for the preparation of unsaturated 4,5-allene ketones by reaction of tertiary propargyl alcohols with alkenyl alkyl ethers or ketals in the presence of aliphatic sulfonic acids or sulfonic acid salts.
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- Polystyrene-supported (catecholato)oxorhenium complexes: Catalysts for alcohol oxidation with DMSO and for deoxygenation of epoxides to alkenes with triphenylphosphine
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Polymer-supported catalysts offer practical advantages for organic synthesis, such as improved product isolation, ease of catalyst recycling, and compatibility with parallel solution-phase techniques. We have developed the (carboxypolystyrene-catecholato)rhenium catalyst 2 derived from tyramine (=4-(2-amino-ethyl)phenol), which is effective for alcohol oxidation with dimethylsulfoxide (DMSO) and for epoxide deoxygenation with triphenylphosphine. The supported [Re(catecholato)]catalyst 2 is air- and moisture-stable and can be recovered and used repeatedly without decreasing activity. The procedures work with non-halogenated solvents (toluene). DMSO for Re-catalyzed alcohol oxidation is inexpensive and safer for transport and storage than commonly used peroxide reagents. The oxidation procedure was best suited for aliphatic alcohols, and the mild conditions were compatible with unprotected functional groups, such as those of alkenes, phenols, nitro compounds, and ketones (see Tables 1 and 2). Selective oxidation of secondary alcohols in the presence of primary alcohols was possible, and with longer reaction time, primary alcohols were converted to aldehydes without overoxidation. Epoxides (oxirans) were catalytically deoxygenated to alkenes with this catalyst and Ph3P (see Table 3). Alkyloxiranes were converted to the alkenes with retention of configuration, while partial isomerization was observed in the deoxygenation of cis-stilbene oxide (cis-1.2-diphenyloxirane). These studies indicate that supported [Re(catecholato)] complexes are effective catalysts for O-atom-transfer reactions, and are well suited for applications in organic synthesis.
- Arterburn, Jeffrey B.,Liu, Minghua,Perry, Marc C.
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p. 3225 - 3236
(2007/10/03)
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- Preparation of gamma , delta -unsaturated ketones by the Carroll reaction, novel catalysts therefor and the preparation thereof
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A process for preparing gamma , delta -unsaturated ketones of the general formula I by reacting an allyl alcohol of the general formula II in which R1 is H or a hydrocarbon radical having 1 to 20 carbon atoms, with diketene or an alkyl acetoacetate of the general formula III in which R2 is alkyl having 1 to 4 carbon atoms in an unmodified or modified Carroll reaction in the presence of an aluminum catalyst, wherein aluminum compounds which are stable liquids at room temperature, or a mixture of such aluminum compounds, which comprise at least one radical formed from an alkyl acetoacetate and 1 or 2 alkoxy radicals, or else comprise exclusively radicals formed from alkyl acetoacetates, which are esterified with sec-butanol or isobutanol, or else are esterified with at least two different alcohols, are used as aluminum catalyst. Also claimed are the novel mixtures of aluminum compounds which comprise radicals which are formed exclusively from alkyl acetoacetates and are esterified with at least two different alkanols, and the batchwise and continuous preparation of the liquid aluminum catalysts.
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- Method for the production of gamma , delta -unsaturated ketones by reacting tertiary allyl alcohols with alkenyl alkyl ethers
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PCT No. PCT/EP97/06425 Sec. 371 Date Jan. 29, 1999 Sec. 102(e) Date Jan. 29, 1999 PCT Filed Nov. 18, 1997 PCT Pub. No. WO98/23570 PCT Pub. Date Jun. 4, 1998An improved process is described for preparing gamma , delta -unsaturated ke-tones, which are in demand as aroma substances and intermediates for vitamins and carotenoids, by reacting tertiary allyl alcohols and alkenyl alkyl ethers in the presence of acid catalysts at elevated temperature, which comprises carrying out the reaction in the presence of a phosphorus derivative of the formula IV where A and B are each a branched or unbranched alkyl or alkoxy having from 1 to 10 carbons, a substituted or unsubstituted aryl, cycloalkyl, aryloxy or cycloaryloxy; A can additionally be -H or -OH or A and B together are a substituted or unsubstituted tetramethylene or pentamethylene or substituted or unsubstituted phenyl-1,2-diol or 1,1'-binaphthyl-2,2'-diol.
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- Epoxides from myrcene: New versatile tools for the synthesis of functionalized acyclic terpenoids
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Mono-epoxides prepared from myrcene, were used as synthetic intermediates to obtain citral, linalool, geranylacetone and pseudo-ionone.
- Fauchet,Miguel, B. Arreguy-San,Taran,Delmond
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p. 3673 - 3684
(2007/10/03)
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- Selective rhenium-catalyzed oxidation of secondary alcohols with methyl sulfoxide in the presence of ethylene glycol, a convenient one-pot synthesis of ketals
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Formula presented Secondary alcohols are oxidized preferentially by DMSO and the catalyst ReOCl3(PPh3)2 in the presence of ethylene glycol and refluxing toluene, producing the corresponding ketals. The reactions are rapid, and proceed in very good to excellent yields. The byproducts of the reaction, methyl sulfide and water, are easily removed. No epoxidation or other common side reactions were observed. This direct oxidative transformation of alcohols to the protected ketal derivatives should have broad synthetic applicability.
- Arterburn, Jeffrey B.,Perry, Marc C.
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p. 769 - 771
(2008/02/12)
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- Process for the preparation of terpenic ketones
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The present invention relates to a process for the preparation of terpenic ketones, which comprises reacting a 1,3-butadiene derivative with a β-keto ester followed by decarbalkoxylation of the product.
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- Stereoselective Synthesis of (E)- and (Z)-γ,δ-Unsaturated Ketones Using trans-2-Phenylthiocyclobutyl Ketones
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The reaction of 1-methoxymethyl-2-phenylthiocyclobutanes with phenylthiotrimethylsilane followed by hydrolysis gave (E)- and (Z)-γ,δ-unsaturated ketones with high stereoselectivity.The starting materials were easily prepared by the stereoselective addition of Grignard reagents to trans-2-phenylthiocyclobutyl ketones.
- Fujiwara, Tooru,Iwasaki, Toshiaki,Takeda, Takeshi
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p. 1321 - 1324
(2007/10/02)
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- 2,3-Epoxy-10-aza-10,11-dihydrosqualene, a High-Energy Intermediate Analogue Inhibitor of 2,3-Oxidosqualene Cyclase
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2,3-Epoxy-10-aza-10,11-dihydrosqualene, a high-energy intermediate analogue inhibitor of 2,3-xidosqualene (SO) cyclase was obtained by total synthesis.This involved the preparation of three main building blocks: (1) C17 squalenoid N-methylamine, (2) 3-(diphenylphosphinoyl)propanal, and (3) 5,6-epoxy-6-methylheptan-2-one.The final stages of the reconstruction of the 6E double bond were obtained by a Wittig-Horner reaction which was modified for poorly reactive systems.This compound was designed to mimic the C-8 carbonium ion formed during SO cyclization.Its inhibitory activity on various SO cyclases was evaluated and compared with the 6 Z isomer which has an unfavorable geometry.Only isomer 6 E, the carbocation analogue, was active on SO cyclases from rat liver, pig liver, S. cerevisiae, and C. albicans microsomes, with an I50 varying from 3 to 5 μM.Both E and Z isomers were inactive on squalene epoxidase at the higher concentrations tested.
- Ceruti, Maurizio,Balliano, Gianni,Viola, Franca,Grosa, Giorgio,Rocco, Flavio,Cattel, Luigi
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p. 3050 - 3058
(2007/10/02)
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- Isoprenoid Chain Elongations by Claisen Rearrangements Using Acetals as Precursors of Vinyl Ethers
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Claisen rearrangements of allyl vinyl ethers, formed in situ by the acid catalyzed reaction of dimethyl acetals of acetaldehyde, acetone and isopropenyl methyl ketone with different types of allylic alcohols, have been compared.The primary, secondary and tertiary allylic alcohols used in the investigation were selected to serve as models for isoprenoid synthesis.The basis for two feasible methods that can be iterated to create isoprenoid chains has been investigated.
- Baeckstroem, Peter,Li, Lanna
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p. 6521 - 6532
(2007/10/02)
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- Allylation of Active Methylene Compounds with Allyl Oxime Carbonates Catalyzed by Pd(0)
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Allylation of active methylene compounds catalyzed by a palladium(0)-phosphine system took place highly stereoselectively by employing allyl oxime carbonates as the allylating reagent.
- Suzuki, Osamu,Hashiguchi, Yoshiharu,Inoue, Seiichi,Sato, Kikumasa
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p. 291 - 294
(2007/10/02)
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- Palladium-Catalyzed Decarboxylation-Allylation of Allylic Esters of α-Substituted β-Keto Carboxylic, Malonic, Cyanoacetic, and Nitroacetic Acids
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Decarboxylation-allylation of allylic β-keto carboxylates using Pd(OAc)2-PPh3 or Pd2(dba)3*CHCl3-dppe as a catalyst proceeds smoothly to give α-allylated ketones.The reaction is highly regioselective.In some cases, diallylated ketones are obtained with allylic esters bearing an active proton(s).Also rhodium, molybdenum, and nickel complexes sre active catalysts in this reaction.Similarly allylic esters of α-substituted malonates, cyanoacetates, and nitroacetate undergo the palladium-catalyzed decarboxylation-allylation to afford allylated acetate, acetonitrile, and nitromethane, respectively.The mechanisms of these palladium-cataly zed decarboxylation-allylations are discussed
- Tsuji, Jiro,,Yamada, Toshiro,Minami, Ichiro,Yuhara, Masami,Nisar, Mohammad,Shimizu, Isao
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p. 2988 - 2995
(2007/10/02)
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- Process for the production of isosolanone and solanone, intermediates useful in said process and organoleptic uses of said intermediates
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Described is a novel genus of compounds defined according to the structure: STR1 wherein Z represents hydrogen, MgX and the moiety having the structure: STR2 and X represents chlor, bromo, or iodo; as well as 5-isopropyl-8-methyl-5,8-nonadien-2-one; uses of same as intermediates in a process for producing isosolanone and solanone; and organoleptic uses of 5-isopropyl-8-methyl-5,8-nonadien-2-one and 2,6-dimethyl-5-methylene-1-hepten-4-ol. The novel process of our invention involved the steps of: (i) formation of the compound having the structure: STR3 by means of reacting 3-methyl-2-methylenebutanal with the compound having the structure: STR4 (ii) acid hydrolysis of the resulting compound in order to form 2,6-dimethyl-5-methylene-1-heptene-4-ol; (iii) reaction of 2,6-dimethyl-5-methylene-1-hepten-4-ol with methyl aceto acetate in order to form 2,6-dimethyl-5-methylene-1-hepten-4-yl aceto acetate or, directly, 5-isopropyl-8-methyl-5,8-nonadiene-2-one; (iv) reacting 2,6-dimethyl-5-methylene-1-hepten-4-yl aceto acetate in the presence of an appropriate catalyst to form the 5-isopropyl-8-methyl-5,8-nonadiene-2-one; and (v) isomerizing the 5-isopropyl-8-methyl-5,8-nonadien-2-one in order to form a mixture of solanone and the isosolanone or 5-isopropyl-8-methyl-5,8-nonadiene-2-one.
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- A Stereospecific Synthesis of (Z)-δ-Halo-γ,δ-unsaturated Ketones via Haloboration Reaction of Terminal Alkynes
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Michael-type reactions of (Z)-β-bromo- and iodoalkenyl-9-borabicyclononanes (5), readily available by haloboration of 1-alkynes, with acyclic α,β-unsaturated ketones (2) in a nonpolar solvent under Lewis acidic conditions are presented.The products, (Z)-δ-halo-γ,δ-unsaturated ketones (6), are obtained in stereochemically pure form (>98 percent).Since the haloalkenylboranes (5) are prepared in situ from haloboranes (4) and 1-alkynes, the present reaction provides a stereospecific, one-pot, and general synthesis of the title compounds (6).When methyl vinyl ketone (MVK) is used as the Michael acceptor, aldol condensation of the intermediate boron enolate with an excess of MVK occurs.However, the aldol (7) is transformed into the parent haloenone (6') without difficulty upon subsequent, in situ treatment with a base.The same product (6') is prepared directly by the reaction with 3-(trimethylsilyl)-3-buten-2-one.Synthetic utility of the present method is demonstrated by selective syntheses of several natural products.Sulcatol (11) is obtained in an overall yield of 63 percent starting from propyne.In a similar manner, trans-geranyl acetone (14) and trans-nerolidol (15) are prepared stereospecifically (>98 percent) in 62 and 72 percent yields, respectively, from 6-methyl-5-hepten-1-yne (12).
- Satoh, Yoshitaka,Serizawa, Hirokazu,Hara, Shoji,Suzuki, Akira
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p. 5225 - 5228
(2007/10/02)
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- Allylic Carbonates. Efficient Allylating Agents of Carbonucleophiles in Palladium-Catalyzed Reactions under Neutral Conditions
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Allylation of β-keto esters or malonates was carried out in good yields under neutral conditions by using allylic carbonates in the presence of palladium-phospine catalyst.Although simple ketones, esters, nitriles, and sulfones hardly react with allylic carbonates, α-alkenyl or α-aryl ketones, esters, nitriles, and sulfones were also allylated by using palladium-bis(diphenylphosphino)ethane catalyst under neutral conditions.
- Tsuji, Jiro,Shimizu, Isao,Minami, Ichiro,Ohashi, Yukihiro,Sugiura, Teruo,Takahashi, Kazuhiko
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p. 1523 - 1529
(2007/10/02)
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- Functionalization of terminal trisubstituted alkenes and derivatives thereof
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The invention relates to a process for preparing compounds having the general structure: STR1 wherein R is hydrogen or an acyclic or alicyclic fragment containing between one and about ten carbon atoms, and R1 is hydrogen or an alkyl containing between one and about four carbon atoms or an aryl group.
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- OZONOLYSIS OF ALKENES AND REACTIONS OF POLYFUNCTIONAL COMPOUNDS. XX. SYNTHESIS OF ACYCLIC a,ω-BIFUNCTIONAL REGULAR (Z)- AND (E)-1,5-POLYENE ISOPRENOIDS
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A new approach was developed to the synthesis of acyclic α,ω-bifunctional (Z)- and (E)-1,5-polyunsaturated isoprenoids, based on the selective ozonolysis of regular (Z)- and (E)-1,4-polyisoprenes.The individual α,ω-dihydroxy derivatives were obtained in the form of bis(trimethylsilyl) ethers and diacetates containing 1-5 (Z)- or (E)-isoprene units, linked "head to tail".Their hydrolysis and oxidation open up the path to stereoregular acyclic isoprenoids with reactive functional groups (hydroxy, keto, aldehyde) at the ends of the chain.
- Odinokov, V. N.,Ignatyuk, V. K.,Tolstikov, G. A.,Rafikov, S. R.
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p. 1230 - 1242
(2007/10/02)
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- Preparation of higher unsaturated ketones
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An improved process for the preparation of higher unsaturated ketones, such as geranylacetone and farnesylacetone, by reacting a β,γ-unsaturated alcohol and an alkyl acetoacetate at an elevated temperature in the presence of an organic aluminum compound, with elimination, and removal, of the alcohol derived from the alkyl acetoacetate in a reactor system carrying a fractionating column. The improvement in the purity, yield, and especially space-time yield of the product is achieved by starting from an alcohol having a higher boiling point than that of the alkyl acetoacetate used, carrying out the reaction in the presence of a small amount of an inert liquid which has a boiling point between that of the alkyl acetoacetate and the alcohol to be eliminated therefrom, and ensuring that the temperature at the bottom of the fractionating column is only slightly higher than the boiling point of the added liquid, under the prevailing pressure.
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- PALLADIUM-CATALYZED REARRANGEMENT OF ALLYLIC ESTERS OF ACETOACETIC ACID TO GIVE γ,δ-UNSATURATED METHYL KETONES
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Various allylic esters of acetoacetic acid undergo rearrangement to give γ,δ-unsaturated methyl ketones in high yields with elimination of carbon dioxide under mild conditions in the presence of catalytic amounts of Pd(OAc)2 and PPh3.
- Shimizu, Isao,Yamada, Toshiro,Tsuji, Jiro
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p. 3199 - 3202
(2007/10/02)
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- Isomerisation cis trans regioselective de doubles liaisons trisubstituees.
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At moderate temperatures aqueous sulphur dioxide equilibrates trisubstituted double bonds.
- Cuvigny,Herve du Penhoat,Julia
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p. 1331 - 1334
(2007/10/02)
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- Process for preparing stereospecific nerolidol and ester thereof
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A process for obtaining a stereospecific nerolidol at the Δ6 -position thereof by rectifying a mixture of Δ6 -cis-nerolidol and Δ6 -trans-nerolidol in rectification column having from 10 to 100 theoretical plates with a reflux ratio of from 2 to 200 at a temperature below 230° C. under reduced pressure to separate each stereospecific nerolidol from said mixture.
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- Inclusion complex compound, process for its production, and method for its use
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An inclusion complex compound comprising (a) meta-cyclophane and (b) a trans-terpenoid of the formula STR1 wherein n is an integer of 1 to 9; A1 and A2 each represent (1) a hydrogen atom, (2) a halogen atom, (3) an inorganic group containing an oxygen, nitrogen or sulfur atom, (4) an organic group containing 1 to 5 carbon atoms, or (5) an organic group containing an oxygen, nitrogen or sulfur atom and 1 to 5 carbon atoms; and C* is the carbon atom of a carbonyl or methylene group, Included by the meta-cyclophane. This inclusion complex compound can be prepared by contacting the meta-cyclophane with a mixture containing the trans-terpenoid. A trans-terpenoid can be separated from a mixture containing it by utilizing an inclusion complex compound of it with meta-cyclophane.
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- Process for the production of substituted ketones
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Process for producing substituted ketones from the reaction between organic halides and ketones having replaceable active hydrogen atoms on the carbon atom(s) alpha to the carbonyl group, in the presence of an alkali metal hydroxide unitilizing phosphonium salts as the catalyst, which salts have the following formula: EQU1 wherein said R1, R2, R3 and R4 are the same or different and are branched or straight chain alkyl of 1-30 carbon atoms, cycloalkyl of 6-10 carbon atoms, aryl of 6-10 carbon atoms aralkyl or alkaryl wherein the aryl and alkyl are as above defined and X- is an inorganic or organic anion.
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- Process for the production of a substituted ketone
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A process for producing substituted ketones is disclosed comprising reacting an organic halide with a ketone which has a replaceable hydrogen atom on the carbon atom in the α-position to the carbonyl group, in the presence of an aqueous alkali metal hydroxide and at least one basic nitrogen catalyst such as certain primary amines, secondary amines, tertiary amines, quaternary ammonium salts or betaine-type quaternary ammonium salts.
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