- SYNTHESIS OF HEPIALONE; PRINCIPAL COMPONENT FROM MALE SEX SCALES OF HEPIALUS CALIFORNICUS (LEPIDOPTERA)
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Racemic and optically active hepialone, a new sex-pheromonal component produced by the male moth, Hepialus californicus Bvd., was synthesized and thus confirmed the structure of the pheromone as (2R)-2,3-dihydro-2-ethyl-6-methyl-4H-pyran-4-one (1).
- Uchino, Keiso,Yamagiwa, Yoshiro,Kamikawa, Tadao,Kubo, Isao
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Read Online
- Asymmetric Synthesis of (1S,3S,5R)-1,3-Dimethyl-2,9-dioxabicyclononane Mediated by Fermenting Bakers' Yeast
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Optically active (1S,3S,5R)-1,3-dimethyl-2,9-dioxabicyclononane has been synthesized in short steps including regio- and enantioselective reduction of 1,3-diketones by actively fermenting bakers' yeast.
- Ohta, Hiromichi,Ozaki, Kazuhiko,Tsuchihashi, Gen-ichi
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Read Online
- Hydrogenation of Esters by Manganese Catalysts
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The hydrogenation of esters catalyzed by a manganese complex of phosphine-aminopyridine ligand was developed. Using this protocol, a variety of (hetero)aromatic and aliphatic carboxylates including biomass-derived esters and lactones were hydrogenated to primary alcohols with 63–98% yields. The manganese catalyst was found to be active for the hydrogenation of methyl benzoate, providing benzyl alcohol with turnover numbers (TON) as high as 45,000. Investigation of catalyst intermediates indicated that the amido manganese complex was the active catalyst species for the reaction. (Figure presented.).
- Li, Xiao-Gen,Li, Fu,Xu, Yue,Xiao, Li-Jun,Xie, Jian-Hua,Zhou, Qi-Lin
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p. 744 - 749
(2022/01/13)
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- Preparation of pyridine derivatives from the corresponding 5-acetal-1-carbonyl compounds by acid promoted cyclization
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The synthesis of four alkylpyridine derivatives from 5-acetal-1-carbonyl compounds via the one-pot, acid-promoted cyclization of oxime intermediates is described. In addition, a dihydroxypyridine and pyridinium salt were also synthesized. The pyridine formation step was not affected by the stereochemistry of the precursors used.
- Konno, Hiroyuki,Mihara, Hiromichi,Watanabe, Yuki
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p. 1314 - 1329
(2021/07/19)
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- Synthesis of deuterated isopentyl pyrophosphates for chemo-enzymatic labelling methods: GC-EI-MS based 1,2-hydride shift in epicedrol biosynthesis
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A sesquiterpene epicedrol cyclase mechanism was elucidated based on the gas chromatography coupled to electron impact mass spectrometry fragmentation data of deuterated (2H) epicedrol analogues. The chemo-enzymatic method was applied for the specific synthesis of 8-position labelled farnesyl pyrophosphate and epicedrol. EI-MS fragmentation ions compared with non-labelled and isotopic mass shift fragments suggest that the 2H of C6 migrates to the C7 position during the cyclization mechanism.
- Said, Madhukar S.,Navale, Govinda R.,Gajbhiye, Jayant M.,Shinde, Sandip S.
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p. 28258 - 28261
(2019/09/30)
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- Unique photoaffinity probes to study TGFβ signaling and receptor fates
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A novel synthetic approach is used to prepare a diverse set of "first-in-class" dihydropyridine-based TGFβ receptor degraders bearing photoaffinity labels. These probes serve as valuable tools to study TGFβ receptor fates and dynamics-an important challenge in chemical biology.
- L?ngle,Wesseler,Fl?tgen,Leek,Plowright,Schade
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supporting information
p. 4323 - 4326
(2019/04/26)
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- COMPOSITIONS FOR THE TREATMENT OF HYPERTENSION AND/OR FIBROSIS
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The present invention relates to novel compounds and their use in the prophylactic and/or therapeutic treatment of hypertension and/or fibrosis.
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Paragraph 00105
(2018/04/20)
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- Synthesis of natural maleimides farinomaleins C-E and evaluation of their antifungal activity
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A practical and convenient synthesis of naturally occurring farinomaleins C-E was achieved starting from readily available ethyl 3-methyl-2-oxobutyrate and triethyl phosphonoacetate. The key steps of the sequence included a Horner-Wadsworth-Emmons condensation to obtain the precursor farinomalein A and coupling with suitable alcohols to install the chain. The synthesis of farinomalein D has been achieved starting from (R)-isopropylideneglycerol on the basis of which the S configuration was assigned to the natural compound. The antifungal activity of the synthesized compounds was evaluated against Cladosporium cladosporioides.
- Lahore, Santosh,Aiwale, Sachin T.,Sardi, Paola,Dallavalle, Sabrina
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p. 4196 - 4198
(2014/07/22)
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- Synthesis of natural maleimides farinomaleins C-E and evaluation of their antifungal activity
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A practical and convenient synthesis of naturally occurring farinomaleins C-E was achieved starting from readily available ethyl 3-methyl-2-oxobutyrate and triethyl phosphonoacetate. The key steps of the sequence included a Horner-Wadsworth-Emmons condensation to obtain the precursor farinomalein A and coupling with suitable alcohols to install the chain. The synthesis of farinomalein D has been achieved starting from (R)-isopropylideneglycerol on the basis of which the S configuration was assigned to the natural compound. The antifungal activity of the synthesized compounds was evaluated against Cladosporium cladosporioides.
- Lahore, Santosh,Aiwale, Sachin T.,Sardi, Paola,Dallavalle, Sabrina
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p. 4196 - 4198
(2015/02/05)
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- A shimizu non-aldol approach to the formal total synthesis of palmerolide A
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A formal total synthesis of palmerolide A has been accomplished by assembling three fragments by means of successive Julia-Kocienski olefination, Yamaguchi esterification, and ring-closing metathesis (RCM). Our initial efforts to combine the first two fragments through a Julia-Kocienski reaction between a secondary sulfone and a ketone were not successful; nevertheless, it was feasible between a primary sulfone and aldehyde. Yamaguchi esterification with the third fragment then set the stage for a RCM reaction. Initial failure of the RCM with a PMB-ether adjacent to the olefins and the difficulty in cleaving the PMB-ether prompted us to change the choice of protecting groups, which then paved the way to the macrocyclic core of palmerolide A.
- Pujari, Sandip A.,Gowrisankar, Parthasarathy,Kaliappan, Krishna P.
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scheme or table
p. 3137 - 3151
(2012/08/28)
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- Benzimidazole compound
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An object of the present invention is to provide a novel chemical compound useful as a therapeutic or prophylactic agent for acid-related diseases, having an excellent inhibitory effect against gastric acid secretion, an excellent effect of maintaining the inhibitory effect against gastric acid secretion, thereby maintaining intragastric pH high for a long time, and having more safety and appropriate physicochemical stability. Provided is a compound represented by where R1 and R3 may be the same or different and each represent a hydrogen atom or a C1-C6 alkyl group; R2 represents (5,5-dimethyl-1,3-dioxan-2-yl)methoxy group, 5,7-dioxaspiro[2.5]oct-6-ylmethoxy group, 1,5,9-trioxaspiro[5.5]undec-3-ylmethoxy group, or (2,2-dimethyl-1,3-dioxan-5-yl)methoxy group; R4, R5, R6 and R7 represent a hydrogen atom, halogen atom, C1-C6 alkyl group, C1-C6 haloalkyl group, C1-C6 alkoxy group or C1-C6 haloalkoxy group; and W1 represents a single bond, methylene or ethylene group, a salt thereof or a solvate of these.
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Page/Page column 84
(2008/06/13)
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- Polysubstituted oxygen heterocycles by a Reformatsky-type reaction/reductive cyclization approach from enantiopure β-ketosulfoxides
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(Chemical Equation Presented) The stereoselective synthesis of tetrasubstituted tetrahydrofurans and trisubstituted tetrahydropyrans bearing a sulfoxide was achieved by reductive cyclization (Et3SiH/TMSOTf) from the corresponding enantiopure hydroxy ketones protected as a dioxolane. These derivatives are easily accessible from a Reformatsky-type reaction between α-bromo-α′-sulfinyl ketones and protected α- or β-ketoaldehydes, followed by diastereoselective reduction of the resulting β-ketosulfoxide.
- Colobert, Francoise,Choppin, Sabine,Ferreiro-Mederos, Leticia,Obringer, Michel,Arratta, Sandra Luengo,Urbano, Antonio,Carreno, M. Carmen
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p. 4451 - 4454
(2008/03/11)
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- Enantioselective microbial hydrolysis of dissymmetrical cyclic carbonates with disubstitution
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Enantioselective microbial hydrolysis of C1 and C2 dissymmetrical cyclic carbonates with disubstitution (methyl and another groups) has been developed. Pseudomonas diminuta (FU0090), a bacterium, efficiently catalyzes the hydrolysis of five-membered cyclic carbonates. While the trans-substrates are hydrolyzed with low enantioselectivities and/or reactivities, the microbe hydrolyzes the cis-substrates with very high enantioselectivities to afford the corresponding almost optically pure anti-(2R,3S)-diols. On the other hand, six-membered trans-cyclic carbonates are enantioselectively hydrolyzed to afford the corresponding optically active syn-(2R,4R)-diols, although the hydrolysis of the cis-substrates gives racemic compounds. In all cases, the enzyme prefers the (R)-enantiomer for the carbon atom bearing a methyl group.
- Nogawa, Masaki,Sugawara, Satomi,Iizuka, Rie,Shimojo, Megumi,Ohta, Hiromichi,Hatanaka, Minoru,Matsumoto, Kazutsugu
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p. 12071 - 12083
(2007/10/03)
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- Total synthesis of topopyrones B and D
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(Chemical Equation Presented) We describe a straightforward synthesis of topopyrones B and D, which are potent and selective inhibitors of topoisomerase I. The chemistry should be suitable for additional structure-activity relationship (SAR) work.
- Tan, Jason Samuel,Ciufolini, Marco A.
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p. 4771 - 4774
(2007/10/03)
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- A novel and stereospecific synthesis of (+)-exo-brevicomin
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A novel and stereospecific synthesis of (+)-exo-brevicomin is disclosed. The key step of the reaction sequence employs the sulfinyl moiety as an intramolecular nucleophile to functionalize an alkene π-complexed to a bromonium ion.
- Raghavan, Sadagopan,Joseph, Suju C.
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p. 8237 - 8239
(2007/10/03)
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- Efficient preparation of 2-methyl-1,3-dioxolane-2-ethanol and 2-(2-bromoethyl)-2-methyl-1,3-dioxolane from 4-hydroxy-2-butanone
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2-Methyl-1,3-dioxolane-2-ethanol was prepared in 90% isolated yield from 4-hydroxy-2-butanone and ethylene glycol using a weak acid catalyst and ethyl acetate as the reaction solvent. 2-(2-Bromoethyl)-2-methyl-1,3-dioxolane was prepared in 75% isolated yield by bromination of 2-Methyl-1,3-dioxolane-2-ethanol with dibromotriphenylphosphorane. The reagent was prepared in situ by titrating triphenylphosphine with bromine at an ice-ethanol bath temperature. The target compounds are useful methyl vinyl ketone equivalents.
- Petroski, Richard J.
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p. 449 - 455
(2007/10/03)
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- Regio- and diastereoselective synthesis of lissoclinolide analogues by Lewis acid catalyzed cyclization of the first 1,5-bis(trimethylsilyloxy)-1,3,5-hexatrienes with oxalyl chloride
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The Lewis acid catalyzed cyclization of 1,5-bis(trimethylsilyloxy)-1,3,5-hexatrienes with oxalyl chloride resulted in formation of polyunsaturated butenolides.
- Langer,Freifeld
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p. 523 - 525
(2007/10/03)
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- Synthesis and immunosuppressive activity of 2-substituted 2- aminopropane-1,3-diols and 2-aminoethanols
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A series of 2-substituted 2-aminopropane-1,3-diols was synthesized and evaluated for their lymphocyte-decreasing effect and immunosuppressive effect on rat skin allograft. A phenyl ring was introduced into the alkyl chain of the lead compound 3, which is an immunosuppressive agent structurally simplified from myriocin (1, ISP-I) via compound 2. The potency of the various compounds was dependent upon the position of the phenyl ring within the alkyl side chain. The most suitable length between the quaternary carbon atom and the phenyl ring was two carbon atoms. 2-Substituted 2-aminoethanols were successively synthesized and evaluated for their T-cell-decreasing effect and immunosuppressive effect using a popliteal lymph node gain assay in rats. The absolute configuration at the quaternary carbon affected the activity, and the (pro-S)-hydroxymethyl group of compound 6 was essential for potent immunosuppressive activity. Favorable substituents for the (pro-R)- hydroxymethyl group of 6 were hydroxyalkyl (hydroxyethyl and hydroxypropyl) or lower alkyl (methyl and ethyl) groups. 2-Amino-2-[2-(4- octylphenyl)ethyl]propane-1,3-diol hydrochloride (6, FTY720) was found to possess considerable activity and is expected to be useful as an immunosuppressive drug for organ transplantation.
- Kiuchi, Masatoshi,Adachi, Kunitomo,Kohara, Toshiyuki,Minoguchi, Masanori,Hanano, Tokushi,Aoki, Yoshiyuki,Mishina, Tadashi,Arita, Masafumi,Nakao, Noriyoshi,Ohtsuki, Makio,Hoshino, Yukio,Teshima, Koji,Chiba, Kenji,Sasaki, Shigeo,Fujita, Tetsuro
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p. 2946 - 2961
(2007/10/03)
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- Study of metal and acid catalysed deprotection of propargyl ethers of alcohols via their allenyl ethers
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A new method for the deprotection of prop-2-ynyl ethers 1b-9b is described. Isomerisation of 1b-9b to O-allenyl ethers 1d-9d and deprotection by reaction with Hg(OCOCF3)2, aq.HCl, aq.CF3CO2H and best by use of a catalytic amount of OsO4 is described to obtain the alcohols 1a-9a in good yield. Application of this method for the deprotection of prop-2-enyl ethers 7c,8c,10c-13c via their corresponding prop-1-enyl ethers 7e,8e,10e-13e to obtain the corresponding alcohols 7a,8a,10a-13a is also described.
- Mereyala, Hari Babu,Gurrala, Srinivas Reddy,Mohan, S. Krishna
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p. 11331 - 11342
(2007/10/03)
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- Potentiation of cADPR-induced Ca2+-release by methylxanthine analogues
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Caffeine and other methylxanthines are known to induce Ca2+-release from intracellular stores via the ryanodine receptor. In the present work, a range of caffeine analogues, in which methyl groups at the 1 and 7 positions were replaced with alkyl chains containing different functional groups (oxo, hydroxyl, propargyl, ester, and acids), were synthesized. These compounds were then screened for their ability to potentiate Ca2+-release induced by cADPR (an endogenous modulator of ryanodine receptors) in sea urchin egg homogenates. Two of the synthesized methylxanthines, 1,3-dimethyl-7-(7- hydroxyoctyl)xanthine (37) and 3-methyl-7-(7-oxooctyl)-1-propargylxanthine (66), were shown to be more potent than caffeine in potentiating cADPR- induced Ca2+-release, while 1,3-dimethyl-7-(5-ethylcarboxypentyl)xanthine (14) was shown to be more efficacious. The development of new methylxanthine analogues may lead to a better understanding of ryanodine receptor function and could possibly provide novel therapeutic agents.
- Cavallaro, Rosaria A.,Filocamo, Luigi,Galuppi, Annamaria,Galione, Antony,Brufani, Mario,Genazzani, Armando A.
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p. 2527 - 2534
(2007/10/03)
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- Synthesis of tetrahydrofurans by a tandem hydrogen atom abstraction/ radical nucleophilic displacement sequence
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(equation presented) The reaction of a series of 5-(N-phthalimidoxy)-1-phenyl-1-(diphenylphosphatoxy)pentanes with triphenyltin hydride and AIBN provides alkoxy radicals which undergo 1,5-hydrogen atom abstraction to give β-(phosphatoxy)alkyl radicals. These radicals then take part in a radical nucleophilic displacement leading, after chain transfer, to tetrahydrofurans.
- Crich, David,Huang, Xianhai,Newcomb, Martin
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p. 225 - 227
(2008/02/12)
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- Studies towards the total synthesis of taxoids: A rapid entry into bicyclo[6.4.0]dodecane ring system. Part 1
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We report a short and stereocontrolled synthesis of the taxoid BC- subunit (+)-5 embodying the whole carbon framework and most of the required oxygen functionalities for further elaboration. Enantiomeric purity was secured at an early stage by resolution
- Arseniyadis, Simeon,Rico Ferreira, Maria Del Rosario,Del Moral, Jose Quilez,Hernando, Jose Ignacio Martin,Potier, Pierre,Toupet, Loic
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p. 4055 - 4071
(2007/10/03)
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- Zeolite H-ZSM 5 Catalysed Oxidation of Alcohols with Chromium Trioxide. Part 9. General Synthetic Methods
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A variety of alcohols are oxidised to the corresponding carbonyl compounds in excellent yields by chromium trioxide-H-ZSM 5 in dichloromethane at room temperature.
- Pitre, Sangeeta V.,Venkat Ram Reddy,Vankar, Yashwant D.
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p. 462 - 463
(2007/10/03)
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- Studies Towards the Total Synthesis of Taxoids: An Efficient Formal Total Synthesis of an A-seco Taxane Framework
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Compounds 6 and 19 embodying the whole carbon framework and suitable functionalities of the taxane skeleton have been assembled starting from readily available chemicals.
- Arseniyadis, S.,Wang, Q.,Yashunsky, D. V.,Kaoudi, T.,Alves, R. Brondi,Potier, P.
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p. 1633 - 1636
(2007/10/02)
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- Polyvinylogation Reagents: 1-Lithio-4-trimethylsiloxy-penta-1,3-diene and 1-Lithio-4-ethoxy-2-methyl-buta-1,3-diene
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Title products, lithiodienol ethers 6a and 7a, synthetic equivalents of 4-lithio pent-3-ene-2-one and 4-lithio-senecialdehyde were obtained by bromine-lithium exchange.They are choice reagents for the transformations 1 -> 2 and 1 -> 3, respectively.
- Duhamel, Lucette,Ancel, Jean-Erick
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p. 9237 - 9250
(2007/10/02)
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- Thermostable Enzymes in Organic Synthesis, Part 6. Total synthesis of (S)-(-)-Zearalenone using a TBADH-Generated Trifunctional Chiron
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Chiral alcohols produced by Thermoanaerobium brockii alcohol dehydrogenase (TBADH)-catalysed asymmetric reduction of polyfunctional ketones are useful building blocks for natural products synthesis.In particular, the ability of TBADH to discriminate between two ketones having equal chemical reactivity is demonstrated by enzymatic reduction of dec-9-ene-2,6-dione to produce optically pure (S)-2-hydroxydec-9-en-6-one.The total synthesis of (S)-(-)-zearalenone with optical purity that exceeds 99.5percent has been achieved by using the latter compound as a starting material.
- Keinan, Ehud,Sinha, Subhash C.,Sinha-Bagchi, Anjana
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p. 3333 - 3340
(2007/10/02)
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- Efficient synthesis of α-(hydroxymethyl) ketones not available through aldol-type processes
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An efficient synthesis of α-(hydroxymethyl) ketones from β-keto esters has been developed, which is experimentally simple, amenable to large scale production and provides products of high purity without resort to chromatography in most cases. The method is a useful alternative and complement to condensation processes.
- Hitchcock,Perron,Martin,Albizati
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p. 1059 - 1061
(2007/10/02)
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- 1,3,5-nonatriene derivatives, their preparation and their use
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1,3,5-Nonatriene derivatives of formula: STR1 in which R1 and R2, together with the carbon atom to which they are linked, form a carbonyl group, or each of R1 and R2 denotes alkoxy or R1 and R2 together form an alkylenedioxy radical, which may be made by reaction of a butadiene derivative of formula: STR2 in which R is alkyl or phenyl, with a butanal ketoacetal of 10 formula: STR3 followed by reaction of the product with a halomethyltriphenylphosphonium halide, are useful intermediates e.g. for the production of phytol.
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- SYNTHESIS OF NATURALLY OCCURRING 2,5-DIALKYLCHROMONES. PART 1. SYNTHESIS OF ALOESONE AND ALOESOL
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A number of 2-alkyl-7-alkoxy ( or hydroxy)-5-methyl-chromones, including naturally occurring aloesone and aloesol, were synthesized starting from ethyl orsellinate via β-keto-sulfoxides as intermediates.
- Gramatica, Paola,Gianotti, M. Pia,Speranza, Giovanna,Manitto, Paolo
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p. 743 - 750
(2007/10/02)
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- REACTIVITE DES DERIVES DE CYCLOPROPYLIDENE-3 PROPYLE-I. SYNTHESE D'ALCOOLS β-CYCLOPROPYLIDENIQUES
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A series of β-cyclopropylidenic alcohols has been synthesized through the following sequence:(i) Wittig condensation between cyclopropylidenetriphenylphosphorane with appropriate monoprotected 1,3-dicarbonyl compounds; (ii)smooth hydrolysis of acetals (after necessary transacetalization step) and ketals thus formed; (iii) LAH reduction of aldehydes and ketones(yielding primary and secondery alcohols respectively) or treatment of ketones with methyllithium (yielding tertiary alcohols).
- Bertrand, M.,Leandri, G.,Meou, A.
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p. 1703 - 1710
(2007/10/02)
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