- 1-Octen-3-ol Is Formed from Its Glycoside during Processing of Soybean [ Glycine max (L.) Merr.] Seeds
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Soaking and maceration of dry soybean seeds induce the formation of aliphatic volatile compounds that impact the flavor properties of food products prepared from soybean. Most aliphatic volatile compounds are formed through oxygenation of unsaturated fatty acids by lipoxygenases; however, lipoxygenases are not responsible for the formation of 1-octen-3-ol. 1-Octen-3-ol in soybean products is in general an off-flavor compound; thus, a procedure to manage its formation is required. In this study, we show that the formation of 1-octen-3-ol after hydration of soybean seed powder is independent of oxygen, suggesting that 1-octen-3-ol is not formed de novo from unsaturated fatty acids but instead from its derivative. When crude methanol extract of soybean seeds was reacted with β-glycosidases, 1-octen-3-ol was rather liberated from its glycoside. We purified the parent glycoside from soybean seeds and confirmed it as (R)-1-octen-3-yl β-primeveroside [(R)-1-octen-3-yl 6-O-β-d-xylopyranosyl-β-d-glucopyranoside]. Green immature soybean fruits (pericarp and seeds) contain a high amount of 1-octen-3-yl β-primeveroside. Its amount decreases after hydration of dry soybean powder. The results indicate that management of 1-octen-3-ol levels in soybean products requires a different strategy than that applied to off-flavor compounds formed de novo.
- Matsui, Kenji,Takemoto, Hiroyuki,Koeduka, Takao,Ohnishi, Toshiyuki
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- A stereoselective synthesis of the reported structure of polyporolide
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Polyporolide, isolated from a basidiomycete, was assigned a 4-hydroxy-5-(1-hydroxyhexyl)-dihydrofuran-2-one structure with anti-placement of the three contiguous stereocenters. A stereoselective total synthesis of the reported structure of the natural product involving two different routes is presented. A comparison of the spectral data of the synthesized molecule indicates the need for structure revision of natural polyporolide.
- Patil, Pradnya H.,Fernandes, Rodney A.
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- A general asymmetric synthesis of (R)-Matsutakeol and flavored analogs
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An efficient and practical synthetic route toward chiral matsutakeol and analogs was developed by asymmetric addition of terminal alkyne to aldehydes. (R)-matsutakeol and other flavored substances were feasibly synthesized from various alkylaldehydes in high yield (up to 49.5%, in three steps) and excellent enantiomeric excess (up to >99%). The protocols may serve as an alternative asymmetric synthetic method for active small-molecule library of natural fatty acid metabolites and analogs. These chiral allyl alcohols are prepared for food analysis and screening insect attractants.
- Liu, Jia,Li, Honglian,Zheng, Chao,Lu, Shichao,Guo, Xianru,Yin, Xinming,Na, Risong,Yu, Bin,Wang, Min
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- Modular enantioselective synthesis of 8-aza-prostaglandin E1
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We report herein for the first time the enantioselective synthesis of 8-aza-PGE1. The synthesis used the cross olefin metathesis reaction to connect the 5-vinyl-γ-lactam subunit, prepared from (R)-malic acid via the Ley's sulfone-based α-amidalkylation protocol (dr = 6.8:1), with the chiral pre-ω-chain. The latter was synthesized in high enantioselectivity from (E)-2-octenol by the Sharpless asymmetric epoxidation and the titanocene-mediated epoxide opening. This modular approach is quite concise and flexible, and requires only eight steps from commercially available reagents.
- Wang, Xiao-Gang,Wang, Ai-E,Hao, Yi,Ruan, Yuan-Ping,Huang, Pei-Qiang
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- Sequential Pd(0)-, Rh(I)-, and Ru(II)-catalyzed reactions in a nine-step synthesis of clinprost
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A step-economical synthesis of clinprost is reported that concludes with 3 different transition metal-catalyzed reactions: Pd-catalyzed decarboxylation with allylic rearrangement, Rh-catalyzed diene-ene [2+2+1] reaction, and Ru-catalyzed cross-metathesis reaction. The complexity bestowed to the molecule from these reactions converts a readily accessible ester to clinprost without using protecting groups in only 9 total steps.
- Nagy, Emma E.,Hyatt, I. F. Dempsey,Gettys, Kristen E.,Yeazell, Shawn T.,Frempong Jr., Stephen K.,Croatt, Mitchell P.
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- Concise, scalable and enantioselective total synthesis of prostaglandins
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Prostaglandins are among the most important natural isolates owing to their broad range of bioactivities and unique structures. However, current methods for the synthesis of prostaglandins suffer from low yields and lengthy steps. Here, we report a practicability-oriented synthetic strategy for the enantioselective and divergent synthesis of prostaglandins. In this approach, the multiply substituted five-membered rings in prostaglandins were constructed via the key enyne cycloisomerization with excellent selectivity (>20:1 d.r., 98% e.e.). The crucial chiral centre on the scaffold of the prostaglandins was installed using the asymmetric hydrogenation method (up to 98% yield and 98% e.e.). From our versatile common intermediates, a series of prostaglandins and related drugs could be produced in two steps, and fluprostenol could be prepared on a 20-gram scale. [Figure not available: see fulltext.]
- Zhang, Fuhao,Zeng, Jingwen,Gao, Mohan,Wang, Linzhou,Chen, Gen-Qiang,Lu, Yixin,Zhang, Xumu
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p. 692 - 697
(2021/06/01)
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- Pickering-Droplet-Derived MOF Microreactors for Continuous-Flow Biocatalysis with Size Selectivity
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Enzymatic microarchitectures with spatially controlled reactivity, engineered molecular sieving ability, favorable interior environment, and industrial productivity show great potential in synthetic protocellular systems and practical biotechnology, but their construction remains a significant challenge. Here, we proposed a Pickering emulsion interface-directed synthesis method to fabricate such a microreactor, in which a robust and defect-free MOF layer was grown around silica emulsifier stabilized droplet surfaces. The compartmentalized interior droplets can provide a biomimetic microenvironment to host free enzymes, while the outer MOF layer secludes active species from the surroundings and endows the microreactor with size-selective permeability. Impressively, the thus-designed enzymatic microreactor exhibited excellent size selectivity and long-term stability, as demonstrated by a 1000 h continuous-flow reaction, while affording completely equal enantioselectivities to the free enzyme counterpart. Moreover, the catalytic efficiency of such enzymatic microreactors was conveniently regulated through engineering of the type or thickness of the outer MOF layer or interior environments for the enzymes, highlighting their superior customized specialties. This study provides new opportunities in designing MOF-based artificial cellular microreactors for practical applications.
- Liang, Linfeng,Shi, Hu,Tian, Danping,Wang, Jun-Hao,Xue, Nan,Yang, Hengquan,Zhang, Xiaoming
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supporting information
p. 16641 - 16652
(2021/10/20)
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- Metathesis at an Implausible Site: A Formal Total Synthesis of Rhizoxin D
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The new approach to the anticancer agent rhizoxin D described herein does not cohere with the conventional logic of metathesis, according to which macrocycles are best closed at a disubstituted olefinic site; rather, the trisubstituted C11?C12 alkene flanked by an allylic -OH group served as the pivot point for synthesis. This motif was attained in good yield and excellent selectivity by a sequence of alkyne metathesis, trans-hydrostannation and cross coupling. Because the exact same substructure is prominently featured in numerous other natural products, the underpinning strategy, though unusual, might bear more general relevance.
- Karier, Pol,Ungeheuer, Felix,Ahlers, Andreas,Anderl, Felix,Wille, Christian,Fürstner, Alois
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supporting information
p. 248 - 253
(2018/12/13)
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- Total synthesis of PGF2α and 6,15-diketo-PGF1α and formal synthesis of 6-keto-PGF1α via three-component coupling
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The asymmetric total synthesis of PGF2α and 6,15-diketo-PGF1α and formal synthesis of 6-keto-PGF1α from a common key intermediate are described. The key intermediate, which has a chiral cyclopentane backbone possessing suitable functional groups with required stereochemistry for both side chains, was prepared from (R)-4-silyloxy-2-cyclopentenone through a three-component coupling reaction. The Wittig reaction, Nozaki-Hiyama-Kishi (NHK) coupling and cross metathesis completed the synthesis of PGF2α, 6,15-diketo-PGF1α and 6-keto-PGF1α.
- Kim, Taehyeong,Lee, Sung Il,Kim, Sejin,Shim, Su Yong,Ryu, Do Hyun
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- Structurally diverse glycoconjugated volatile compounds from Oxytropis falcata Bunge
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A phytochemical investigation on the whole plant of Oxytropis falcata Bunge yielded 16 glycoconjugated compounds with structurally diverse volatile aglycones but similar sugars. Of these, five were previously undescribed compounds with different volatile aglycones but same glucuronic acid (1 → 2) glucosyl moiety, including three octanol glucuronic acid (1 → 2) glucosides (1–3), one acyclic monoterpenoid glucuronic acid (1 → 2) glucoside (4), and one 4-phenyl-butan-2-ol glucuronic acid (1 → 2) glucoside (5), and 11 were biological related known glucoconjugated volatile compounds (6–16) isolated from genus Oxytropis for the first time. The structures of these compounds were determined by extensive spectroscopic analysis of MS, 1D and 2D NMR data. The absolute configurations of aglycones and sugar residues were assigned via enzymatic hydrolysis and subsequently comparison of the specific rotations. This is the first report of such structurally diverse glycoconjugated volatile compounds from O. falcata, which might be regarded as the precursor of free volatile compounds, and presents scientific evidences for better clarifying the volatile compositions of this medicinal plant and genus Oxytropis.
- Wang, Shanshan,Zhang, Xiaojing,Que, Sheng,Liang, Hong,Tu, Pengfei,Zhang, Qingying
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p. 143 - 147
(2018/07/29)
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- Regioselective Asymmetric Allylic Alkylation Reaction of α -Cyanoacetates Catalyzed by a Heterobimetallic Platina-/Palladacycle
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Allylic substitution reactions provide a valuable tool for the functionalization of CH acidic pronucleophiles. Often, control over the stereocenter generated at the nucleophilic reactant is still a challenge. The majority of studies that address this issue employ metal complexes with a low metal oxidation state (e.g. Pd0) to form allyl complexes through oxidative addition. In this article we describe the use of heterobimetallic PtII/PdII complexes, which probably activate the olefinic substrates through an SN2′ pathway. The reaction of α-cyanoacetates delivers linear allylation products with exclusive regioselectivity and high E/Z-selectivity for the new C=C double bond. Although the enantioselectivities attained are moderate, they are significantly higher than with related mono-PdII or -PtII catalysts or the corresponding bis-PdII complex, which indicates cooperation of the different metals. Control experiments suggest simultaneous activation of both reaction partners.
- Weiss, Marcel,Holz, Julia,Peters, Ren
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p. 210 - 227
(2016/01/20)
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- Fungal mediated kinetic resolution of racemic acetates to (R)-alcohols using Fusarium proliferatum
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Fungal mediated kinetic resolution of seven acyclic/aromatic acetates was achieved using Fusarium proliferatum to furnish (R)-alcohols in high enantiomeric excess (>95%). The kinetic resolution was established as one-pot two-step de-esterification/oxidation biocatalytic process. Further, the preparative scale synthesis of (R)-(+)-1-phenylethanol was accomplished through de-esterification/oxidation of (±)-1-phenylethyl acetate using the whole cell of F. proliferatum NCIM 1105.
- Jadhav, Dipesh D.,Patil, Harshal S.,Chaya, Patil S.,Thulasiram, Hirekodathakallu V.
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p. 4563 - 4567
(2016/09/23)
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- Chemoenzymatic asymmetric total synthesis of nonanolide (Z)-cytospolides D, E and their stereoisomers
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Chemoenzymatic asymmetric total synthesis of the (Z)-isomer of the naturally occurring decanolide cytospolides D, E and six stereoisomers is reported. The main highlight of the synthetic venture involves ring-closing metathesis (RCM) reaction of a suitably functionalized ester compound, which was assembled by the Yamaguchi coupling of the required acid and alcohol fragments. The alcohol fragment was ac- cessed by two alternative chemoenzymatic processes, one being hydroxynitrile lyase mediated hydrocyanation, whereas lipase-catalyzed transesterification was the key sep in the second route. The acid fragment was constructed by an enantioselective enzymatic desymmetrization (EED) of prochiral 2-methyl-1,3-propanediol and Corey-Bakshi-Shibata (CBS) mediated stereoselective carbonyl reduction.
- Rej, Rohan Kalyan,Nanda, Samik
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p. 860 - 871
(2014/03/21)
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- Chemoenzymatic Asymmetric Total Synthesis of Nonanolide (Z)-Cytospolides D, e and Their Stereoisomers
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Chemoenzymatic asymmetric total synthesis of the (Z)-isomer of the naturally occurring decanolide cytospolides D, E and six stereoisomers is reported. The main highlight of the synthetic venture involves ring-closing metathesis (RCM) reaction of a suitably functionalized ester compound, which was assembled by the Yamaguchi coupling of the required acid and alcohol fragments. The alcohol fragment was accessed by two alternative chemoenzymatic processes, one being hydroxynitrile lyase mediated hydrocyanation, whereas lipase-catalyzed transesterification was the key sep in the second route. The acid fragment was constructed by an enantioselective enzymatic desymmetrization (EED) of prochiral 2-methyl-1,3-propanediol and Corey-Bakshi-Shibata (CBS) mediated stereoselective carbonyl reduction.
- Rej, Rohan Kalyan,Nanda, Samik
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p. 860 - 871
(2015/10/05)
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- Arachidonic acid-dependent carbon-eight volatile synthesis from wounded liverwort (Marchantia polymorpha)
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Eight-carbon (C8) volatiles, such as 1-octen-3-ol, octan-3-one, and octan-3-ol, are ubiquitously found among fungi and bryophytes. In this study, it was found that the thalli of the common liverwort Marchantia polymorpha, a model plant species, emitted high amounts of C8 volatiles mainly consisting of (R)-1-octen-3-ol and octan-3-one upon mechanical wounding. The induction of emission took place within 40 min. In intact thalli, 1-octen-3-yl acetate was the predominant C8 volatile while tissue disruption resulted in conversion of the acetate to 1-octen-3-ol. This conversion was carried out by an esterase showing stereospecificity to (R)-1-octen-3-yl acetate. From the transgenic line of M. polymorpha (des6KO) lacking arachidonic acid and eicosapentaenoic acid, formation of C8 volatiles was only minimally observed, which indicated that arachidonic and/or eicosapentaenoic acids were essential to form C8 volatiles in M. polymorpha. When des6KO thalli were exposed to the vapor of 1-octen-3-ol, they absorbed the alcohol and converted it into 1-octen-3-yl acetate and octan-3-one. Therefore, this implied that 1-octen-3-ol was the primary C8 product formed from arachidonic acid, and further metabolism involving acetylation and oxidoreduction occurred to diversify the C8 products. Octan-3-one was only minimally formed from completely disrupted thalli, while it was formed as the most abundant product in partially disrupted thalli. Therefore, it is assumed that the remaining intact tissues were involved in the conversion of 1-octen-3-ol to octan-3-one in the partially disrupted thalli. The conversion was partly promoted by addition of NAD(P)H into the completely disrupted tissues, suggesting an NAD(P)H-dependent oxidoreductase was involved in the conversion.
- Kihara, Hirotomo,Tanaka, Maya,Yamato, Katsuyuki T.,Horibata, Akira,Yamada, Atsushi,Kita, Sayaka,Ishizaki, Kimitsune,Kajikawa, Masataka,Fukuzawa, Hideya,Kohchi, Takayuki,Akakabe, Yoshihiko,Matsui, Kenji
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supporting information
p. 42 - 49
(2015/02/19)
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- Stereochemistry and mechanism of enzymatic and non-enzymatic hydrolysis of benzylic sec-sulfate esters
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The substrate scope of inverting alkylsulfatase Pisa1 was extended towards benzylic sec-sulfate esters by suppression of competing non-enzymatic autohydrolysis by addition of dimethyl sulfoxide as co-solvent. Detailed investigation of the mechanism of autohydrolysis in 18O-labeled buffer by using an enantiopure sec-benzylic sulfate ester as substrate revealed that from the three possible pathways (i) inverting SN2-type nucleophilic attack of [OH-] at the benzylic carbon represents the major pathway, whereas (ii) SN1-type formation of a planar benzylic carbenium ion leading to racemization was a minor event, and (iii) Retaining SN2-type nucleophilic attack at sulfur took place at the limits of detection. The data obtained are interpreted by analysis of Hammett constants of meta substituents. The enzymatic hydrolysis of benzylic sec-sulfate esters by alkylsulfatase Pisa1 proceeded with clean inversion of configuration and with excellent stereoselectivities when the competing non-enzymatic hydrolysis was suppressed by addition of dimethyl sulfoxide as co-solvent. Copyright
- Toesch, Michael,Schober, Markus,Breinbauer, Rolf,Faber, Kurt
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p. 3930 - 3934
(2014/06/24)
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- Clinprost, Isocarbacyclin And Analogs Thereof And Methods Of Making The Same
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In one aspect, methods of synthesizing clinprost, isocarbacyclin and analogs thereof are described herein which, in some embodiments, permit an abbreviated synthetic pathway in comparison to one or more prior synthetic methods. By providing a compact synthetic scheme, methods described herein can reduce cost, waste and time of clinprost and isocarbacyclin synthesis while facilitating the development and investigation of analogs of these compounds.
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- Scopariusic acid, a new meroditerpenoid with a unique cyclobutane ring isolated from Isodon scoparius
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Scopariusic acid (1), a new ent-clerodane-based meroditerpenoid with a unique cyclobutane ring and an unusual 1-octen-3-ol substituent, together with its biosynthetic related compound 2, were isolated from the aerial parts of Isodon scoparius. The structures of 1 and 2, including their absolute configurations, were determined by spectroscopic methods, single-crystal X-ray diffraction analysis, and chemical methods. Compound 1 showed weak cytotoxicity and moderate immunosuppressive activity.
- Zhou, Min,Zhang, Hai-Bo,Wang, Wei-Guang,Gong, Ning-Bo,Zhan, Rui,Li, Xiao-Nian,Du, Xue,Li, Li-Mei,Li, Yan,Lu, Yang,Pu, Jian-Xin,Sun, Han-Dong
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supporting information
p. 4446 - 4449
(2013/09/24)
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- Selective syntheses of Δα,β and Δβ,γ butenolides from allylic cyclopropenecarboxylates via tandem ring expansion/[3,3]-sigmatropic rearrangements
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Allylic cyclopropenecarboxylates undergo ring expansion reactions to give 2-allyloxyfuran intermediates, which subsequently rearrange to Δβ,γ butenolides via a Claisen rearrangement or to the corresponding Δα,β butenolides via further Cope rearrangement. Also described are methods for chirality transfer in the rearrangement of nonracemic allylic esters.
- Xie, Xiaocong,Li, Yi,Fox, Joseph M.
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supporting information
p. 1500 - 1503
(2013/07/05)
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- The substrate spectrum of the inverting sec-alkylsulfatase Pisa1
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The substrate spectrum of the inverting alkylsulfatase Pisa1 was investigated using a range of sec-alkyl sulfate esters bearing aromatic, olefinic and acetylenic moieties. Perfect enantioselectivities were obtained for substrates bearing groups of different size adjacent to the sulfate ester moiety. Insufficient selectivities could be doubled by using dimethyl sulfoxide (DMSO) as co-solvent. Hydrolytically unstable benzylic sulfate esters could be sufficiently stabilised by introduction of electron-withdrawing substituents. Overall, Pisa1 appears to be a very useful inverting alkylsulfatase for the deracemisation of rac-sec-alcohols via enzymatic hydrolysis of their corresponding sulfate esters, which furnishes homochiral products possessing the 'anti-Kazlauskas' configuration. Copyright
- Schober, Markus,Knaus, Tanja,Toesch, Michael,MacHeroux, Peter,Wagner, Ulrike,Faber, Kurt
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p. 1737 - 1742
(2012/07/31)
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- A convenient access to γ-lactones from O-allyl-α-bromoesters using a one-pot ionic-radical-ionic sequence
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Cognac in the jar! An efficient one-pot sequence for the preparation of γ-lactones is described. Following reduction of α-bromo ester precursors with DIBAL-H and radical cyclization of the resulting O-aluminum acetals, a preparative in-situ Oppenauer-type oxidation of the cyclic O-aluminum acetal using simple aldehydes or ketones gives access to γ-lactones in high yields. Copyright
- Beneteau, Romain,Lebreton, Jacques,Denes, Fabrice
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supporting information; experimental part
p. 1516 - 1520
(2012/09/08)
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- Syntheses of enantiopure aliphatic secondary alcohols and acetates by bioresolution with lipase B from candida antarctica
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The lipase B from Candida antarctica (Novozym 435, CALB) efficiently catalyzed the kinetic resolution of some aliphatic secondary alcohols: (±)-4-methylpentan- 2-ol (1), (±)-5-methylhexan-2-ol (3), (±)-octan-2-ol (4), (±)-heptan-3-ol (5) and (±)-oct-1- en-3-ol (6). The lipase showed excellent enantioselectivities in the transesterifications of racemic aliphatic secondary alcohols producing the enantiopure alcohols (>99% ee) and acetates (>99% ee) with good yields. Kinetic resolution of rac-alcohols was successfully achieved with CALB lipase using simple conditions, vinyl acetate as acylating agent, and hexane as non-polar solvent.
- Ferreira, Hercules V.,Rocha, Lenilson C.,Severino, Richele P.,Porto, Andre L. M.
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p. 8955 - 8967,13
(2020/08/31)
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- The first stereoselective total synthesis of the Z-isomer of cytospolide e
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A convergent and highly stereoselective total synthesis of the Z-isomer of cytospolide E has been achieved via Evan's aldol reaction, Sharpless kinetic resolution and RCM cyclisation.
- Yadav,Pandurangam,Suman Kumar,Adi Narayana Reddy,Prasad,Reddy, B.V. Subba,Rajendraprasad,Kunwar
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p. 6048 - 6050
(2012/11/07)
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- Ruthenium-catalyzed regio- and enantioselective allylic substitution with water: Direct synthesis of chiral allylic alcohols
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Less is more: A new route to access chiral allylic alcohols through the regio- and enantioselective substitution of monosubstituted allylic chlorides with water has been developed. The reaction is catalyzed effectively by planar-chiral cyclopentadienyl ruthenium complexes (see scheme). Copyright
- Kanbayashi, Naoya,Onitsuka, Kiyotaka
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supporting information; experimental part
p. 5197 - 5199
(2011/06/26)
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- Highly efficient kinetic resolution of allylic alcohols with terminal double bond
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In this study, the lipase-catalyzed kinetic resolution (Novozyme 435) was employed to prepare chiral allylic alcohols and acetates with terminal double bonds in enantiomeric excesses ranging from 94 to >99 %.
- Marques, Francisco A.,Oliveira, Marcos A.,Frensch, Gustavo,Sales Maia, Beatriz Helena L. N.,Barison, Andersson,Lenz, Cesar A.,Guerrero Jr., Palimecio G.
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p. 696 - 700
(2012/06/04)
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- Deracemization of secondary alcohols through a concurrent tandem biocatalytic oxidation and reduction
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(Chemical Equation Presented) Breaking the mirror: A purified alcohol dehydrogenase (ADH) for stereoselective reduction and whole cells of a microorganism for enantioselective oxidation operated concurrently to effect the stereoinversion of one enantiomer of a racemic secondary alcohol and provide the optically pure alcohol in >99% yield (see scheme). R,R′ = alkyl.
- Voss, Constance V.,Gruber, Christian C.,Kroutil, Wolfgang
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p. 741 - 745
(2008/12/20)
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- Metabolism of deuterated erythro-dihydroxy fatty acids in Saccharomyces cerevisiae: Enantioselective formation and characterization of hydroxylactones
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Epoxides of fatty acids are hydrolyzed by epoxide hydrolases (EHs) into dihydroxy fatty acids which are of particular interest in the mammalian leukotriene pathway. In the present report, the analysis of the configuration of dihydroxy fatty acids via their respective hydroxylactones is described. In addition, the biotransformation of (±)-erythro-7,8- and -3,4-dihydroxy fatty acids in the yeast Saccharomyces cerevisiae was characterized by GC/EI-MS analysis. Biotransformation of chemically synthesized (±)-erythro-7,8- dihydroxy(7,8-2H2)tetradecanoic acid ((±)-erythro- 1) in the yeast S. cerevisiae resulted in the formation of 5,6-dihydroxy(5,6- 2H2)dodecanoic acid (6), which was lactonized into (5S,6R)-6-hydroxy(5,6-2H2)dodecano-5-lactone ((5S,6R)-4) with 86% ee and into erythro-5-hydroxy(5,6-2H2)dodecano-6- lactone (erythro-8). Additionally, the α-ketols 7-hydroxy-8-oxo(7- 2H1)tetradecanoic acid (9a) and 8-hydroxy-7-oxo(8- 2H1)tetradecanoic acid (9b) were detected as intermediates. Further metabolism of 6 led to 3,4-dihydroxy(3,4- 2H2)decanoic acid (2) which was lactonized into 3-hydroxy(3,4-2H2)decano-4-lactone (5) with (3R,4S)-5=88% ee. Chemical synthesis and incubation of (±)-erythro-3,4-dihydroxy(3,4- 2H2)decanoic acid ((±)-erythro-2) in yeast led to (3S,4R)-5 with 10% ee. No decano-4-lactone was formed from the precursors 1 or 2 by yeast. The enantiomers (3S,4R)- and (3R,4S)-3,4-dihydroxy(3- 2H1)nonanoic acid ((3S,4R)- and (3R,4S)-3) were chemically synthesized and comparably degraded by yeast without formation of nonano-4-lactone. The major products of the transformation of (3S,4R)- and (3R,4S)-3 were (3S,4R)- and (3R,4S)-3-hydroxy(3-2H 1)nonano-4-lactones ((3S,4R)- and (3R,4S)-7), respectively. The enantiomers of the hydroxylactones 4, 5, and 7 were chemically synthesized and their GC-elution sequence on Lipodex E chiral phase was determined.
- Garbe, Leif-A.,Morgenthal, Katja,Kuscher, Katrin,Tress, Roland
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experimental part
p. 993 - 1007
(2009/02/07)
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- Atom transfer radical cyclization (ATRC) applied to a chemoenzymatic synthesis of Quercus lactones
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The natural fragrances (+)-trans whisky lactone 2 and (+)-trans cognac lactone 4, together with a minor amount of their (-)-cis stereoisomers, were prepared in 50% and 42% overall yield, respectively, starting from racemic 1-hepten-3-ol (±)-5 and 1-octen-3-ol (±)-6. The procedure involved first the enantioconvergent, lipase mediated transformation of the secondary allylic alcohols derived dichloroacetates (±)-7 and (±)-8 into the corresponding homochiral (+)-7 and (+)-8, combined with their cyclization under a transition metal catalyzed atom transfer process.
- Felluga, Fulvia,Forzato, Cristina,Ghelfi, Franco,Nitti, Patrizia,Pitacco, Giuliana,Pagnoni, Ugo Maria,Roncaglia, Fabrizio
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p. 527 - 536
(2007/10/03)
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- Copper-catalyzed enantioselective substitution of allylic carbonates with diboron: An efficient route to optically active α-chiral allylboronates
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A method for the synthesis of α-chiral allylboronates featuring the Cu(I)-catalyzed enantioselective substitution of readily available allylic carbonates with a diboron is described. Using this method, various α-chiral allylboronates, including functionalized allylboronates, were successfully synthesized, with high enantiomeric purity. Copyright
- Ito, Hajime,Ito, Shinichiro,Sasaki, Yusuke,Matsuura, Kou,Sawamura, Masaya
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p. 14856 - 14857
(2008/09/19)
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- Radical cyclization route to the stereoselective synthesis of ( )-trans-cognac lactone and ( )-trans-aerangis lactone
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Stereoselective total synthesis of two chiral lactones, (+)-trans-cognac lactone (1b) and (+)-trans-aerangis lactone (2c), has been achieved from the same intermediate using a radical-based cyclization route. Copyright Taylor & Francis Group, LLC.
- Sabitha, Gowravaram,Bhikshapathi,Yadav
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p. 561 - 569
(2007/10/03)
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- Chemoenzymatic synthesis of optically active γ-alkyl-γ-butenolides
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rac-Hept-1-en-3-ol 4 was subjected to an enantioselective esterification in the presence of Novozyme 435 and vinyl crotonate as the acyl donor to give (3S)-oct-1-en-3-yl crotonate 7 in >99% ee and (3R)-alcohol 4 in 99% ee. The E-value of this enzymatic reaction was found to be >1000. The (S)-crotonic ester 7 was converted by ring-closing metathesis (RCM) using Grubbs' catalyst to give (S)-oct-2-en-4-olide 1 in 96% yield while keeping the high enantiomeric excess.
- Fujii, Mikio,Fukumura, Motonori,Hori, Yumiko,Hirai, Yasuaki,Akita, Hiroyuki,Nakamura, Kaoru,Toriizuka, Kazuo,Ida, Yoshiteru
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p. 2292 - 2298
(2007/10/03)
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- Effect of allylic and homoallylic substituents on cross metathesis: syntheses of prostaglandins F2α and J2
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We describe the effect of allylic (C15) and homoallylic (C11) substituents on cross metathesis reactions with Corey lactone derivatives. This strategy has led to the successful syntheses of PGF2α and PGJ2.
- Sheddan, Neil A.,Arion, Vladimir B.,Mulzer, Johann
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p. 6689 - 6693
(2007/10/03)
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- Biocatalytic deuterium- and hydrogen-transfer using over-expressed ADH-'A': Enhanced stereoselectivity and 2H-labeled chiral alcohols
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Employing the over-expressed highly organic solvent tolerant alcohol dehydrogenase ADH-'A' from Rhodococcus ruber DSM 44541, versatile building blocks, which were not accessible by the wild type catalyst, were obtained in > 99% e.e.; furthermore, employing d8-2-propanol as deuterium source, stereoselective biocatalytic deuterium transfer was made feasible to furnish enantiopure deuterium labeled sec-alcohols on a preparative scale employing a single enzyme. The Royal Society of Chemistry 2006.
- Edegger, Klaus,Gruber, Christian C.,Poessl, Tina M.,Wallner, Sabine R.,Lavandera, Ivan,Faber, Kurt,Niehaus, Frank,Eck, Juergen,Oehrlein, Reinhold,Hafner, Andreas,Kroutil, Wolfgang
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p. 2402 - 2404
(2008/03/28)
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- Preparation of single-enantiomer semiochemicals using 2-methoxy-2-(1- naphthyl)propionic acid and 2-methoxy-2-(9-phenanthryl)propionic acid
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Enantioresolution of 3-octanol, 6-methyl-5-hepten-2-ol (sulcatol), and 1-octen-3-ol was conducted using (S)-(+)-2-methoxy-2-(1-naphthyl)propionic acid (MαNP acid) and (S)-(+)-2-methoxy-2-(9-phenanthryl)propionic acid (M9PP acid). In each case, the diastereomeric esters obtained were readily separated by HPLC. The stereochemistry of the esters could be assigned from their respective 1H NMR analyses. Solvolyses of the esters gave enantiopure alcohols and acids. MαNP and M9PP acids displayed almost equivalent properties in 1H NMR anisotropy. The chiral resolving ability of M9PP acid was slightly superior to that of MαNP acid in HPLC.
- Ichikawa, Akio,Ono, Hiroshi
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p. 2559 - 2568
(2007/10/03)
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- A straightforward synthesis of (-)-phaseolinic acid
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A concise approach to (-)-phaseolinic acid starting from commercially available (S)-oct-1-yn-3-ol is disclosed. The key steps are a ring-closing metathesis reaction to prepare a C2-symmetrical allylic diol and its desymmetrization to a γ-butyrolactone by using an Ireland-Claisen rearrangement. The 2S,3S,4S configuration of the levogyre natural product has been confirmed.
- Amador, Marta,Ariza, Xavier,Garcia, Jordi,Ortiz, Jordi
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p. 8172 - 8175
(2007/10/03)
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- Site-specific synthesis and reactivity of oligonucleotides containing stereochemically defined 1,N2-deoxyguanosine adducts of the lipid peroxidation product trans-4-Hydroxynonenal
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trans-4-Hydroxynonenal (HNE) is a major peroxidation product of ω-6 polyunsaturated fatty acids. The reaction of HNE with DNA gives four diastereomeric 1,N2-γ-hydroxypropano adducts of deoxyguanosine; background levels of these adducts have been detected in animal tissue. Stereospecific syntheses of these four adducts at the nucleoside level have been accomplished. In addition, a versatile strategy for their site-specific incorporation into oligonucleotides has been developed. These adducts are destabilizing as measured by melting temperature when compared to an unadducted strand. The thermal destablization of the adducted 12-mers ranged from 5 to 16 °C and is dependent on the absolute stereochemistry of the adduct. The HNE adducts were also examined for their ability to form interstrand DNA-DNA cross-links when incorporated into a CpG sequence. We find that only one of the HNE stereoisomers formed interstrand DNA-DNA cross-links.
- Wang, Hao,Kozekov, Ivan D.,Harris, Thomas M.,Rizzo, Carmelo J.
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p. 5687 - 5700
(2007/10/03)
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- Asymmetric reduction of α-(trimethylsilyl)methyl-β-ketosulfoxide with DIBAL under basic conditions
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The reaction of the α-carbanion of p-tolyl 2-(trimethylsilyl)ethyl sulfoxide with esters followed by reduction with DIBAL gave α-(trimethylsilyl)methyl-β-hydroxysulfoxides with high stereoselectivity. The stereoselective reaction was demonstrated to proceed through a dynamic kinetic resolution pathway via a six-membered cyclic transition state involving Si-O interaction. These reactions provide a convenient route for the synthesis of optically pure allylic alcohols.
- Nakamura, Shuichi,Nakayama, Jun-ichi,Toru, Takeshi
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p. 5766 - 5768
(2007/10/03)
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- Chemical constituents of two oriental orchids, Calanthe discolor and C. liukiuensis: Precursor indole glycoside of tryptanthrin and indirubin
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Two indole glycosides, calanthoside and glucoindican, were isolated from two oriental orchids, Calanthe discolor LINDL. and C. liukiuensis SCHLTR., together with calaphenanthreol, calaliukiuenoside, and bioactive known alkaloids, tryptanthrin, indirubin, and isatin. The structures of calanthoside, glucoindican, calaphenanthreol, and calaliukiuenoside were determined on the basis of physicochemical and chemical evidence. Furthermore, it was found that enzymatic hydrolysis of calanthoside furnished tryptanthrin as the main product, whereas indirubin and isatin were obtained by acid hydrolysis of calanthoside.
- Murakami, Toshiyuki,Kishi, Akinobu,Sakurama, Tetsuo,Matsuda, Hisashi,Yoshikawa, Masayuki
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p. 957 - 966
(2007/10/03)
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- Characterization and synthesis of (-)-7-methoxydodec-4(E)-enoic acid, a novel fatty acid isolated from Lyngbya majuscula
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The isolation and characterization of (-)-7-methoxydodec-4(E)-enoic acid, a novel fatty acid isolated from the marine Cyanophyte Lyngbya majuscula collected off the French Mediterranean coast are described. The synthesis of this acid and three of its isomers is reported.
- Mesguiche, Veronique,Valls, Robert,Piovetti, Louis,Peiffer, Gilbert
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p. 7473 - 7476
(2007/10/03)
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- Thiacrown ether as regulator of lipase-catalyzed trans-esterification in organic media: Practical optical resolution of allyl alcohols
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Thiacrown either additive enhanced enantioselectivity in lipase- catalyzed trans-esterification of allyl alcohols. Small amounts of thiacrown ether offered highly enantioselective reaction when 5-phenylpentene-3-ol was subjected to the reaction of Pseudomonas cepacia lipase.
- Takagi, Yumiko,Teramoto, Jun,Kihara, Hiroshi,Itoh, Toshiyuki,Tsukube, Hiroshi
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p. 4991 - 4992
(2007/10/03)
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- Enzymatic Hydrolysis of Alken- and Alkyn-3-ol Acetates in an Acetone-Water Solvent System: Effect of Unsaturation on the Enantioselectivity of Pseudomonas cepacia Lipase-catalyzed Hydrolysis
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High enentioselectivity was observed for the Pseudomonas cepacia lipase-catalyzed hydrolysis of (E)-allylic acetate 1 and propargylic acetate 2 in an acetone-water solvent system, while (E)-homoallylic acetate 3 and homopropargylic acetate 4 gave poor enantioselectivity.
- Kamezawa, Makoto,Raku, Takao,Tachibana, Hojun,Ohtani, Takehiko,Naoshima, Yoshinobu
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p. 549 - 551
(2007/10/02)
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- Vinyl Anion Equivalent V. Asymmetric Synthesis of Allylic Alcohols Using Chiral 2-(Trialkylsilyl)ethyl Sulfoxides
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Both enantiomers of optically pure secondary allylic alcohols can be conveniently prepared by the diastereoselective reaction of the α-sulfinyl carbanion of p-tolyl 2-(trialkylsilyl)ethyl sulfoxides or tert-butyl 2-(trimethylsilyl)ethyl sulfoxide with aldehydes followed by either fluoride-induced desilylsulfinylation or thermal elimination of the sulfinyl group.
- Kusuda, Shinya,Ueno, Yoshio,Toru, Takeshi
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p. 1045 - 1062
(2007/10/02)
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- Synthesis of Optically Active Secondary Allylic Alcohols from Allylsilanes via Successive Asymmetric Dihydroxylation (AD) and Peterson Olefination Reaction
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Optically active, secondary allylic alcohols can be prepared from allylic silanes by the successive asymmetric dihydroxylation and Peterson olefination reactions.The effects of trialkylsilyl groups on the outcome of the AD reaction on vinyl and allyl silanes are also discussed.
- Okamoto, Sentaro,Tani, Kousuke,Sato, Fumie,Sharpless, K. Barry,Zargarian, Davit
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p. 2509 - 2512
(2007/10/02)
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- Synthesis of optically active allylic alcohols
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A practical and enantiospecific method for the synthesis of optically pure allylic alcohols [(R)- or (S)-1-alken-3-ols] is described. The key reaction is the reductive cleavage of the cyclic carbonates of 1-halo-2,3-alkanediols with zinc, magnesium, or samarium diiodide.
- Kang,Kim,Cho,Jeon
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p. 681 - 684
(2007/10/02)
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- A Tellurium Transposition Route to Allylic Alcohols: Overcoming Some Limitations of the Sharpless-Katsuki Asymmetric Epoxidation
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Good yields of enantiomeric allylic alcohols can be obtained in high enantiomeric excess (ee) by combining Sharpless-Katsuki asymmetric epoxidation process (SAE) with tellurium chemistry.The advantages of the tellurium process are as follows: (1) the 50percent yield limitation on the allylic alcohol in the Sharpless kinetic resolution (SKR) can be overcome; (2) allylic tertiary alcohols which are unsatisfactory substrates in the SKR can be obtained in high optical purity; (3) optically active secondary allylic alcohols with tertiary alkyl substituents (e.g. tert-butyl) at C-1 can be obtained in high ee; (4) optically active sterically congested cis secondary alcohols can be obtained in high ee; and (5) the nuisance of the slow SAE of some vinyl carbinols can be avoided.The key step in the reaction sequence is either a stereospecific 1,3-transposition of double bond and alcohol functionalities or an inversion of the alcohol configuration with concomitant deoxygenation of the epoxide function in epoxy alcohols.Trans secondary allylic alcohols can be converted to cis secondary allylic alcohols by way of erythro epoxy alcohols (glycidols); threo glycidyl derivatives are converted to trans secondary allylic alcohols.These transformations are accomplished by the action of telluride ion, generated in situ from the element, on a glycidyl sulfonate ester.Reduction of elemental Te is conveniently done with rongalite (HOCH2SO2Na) in an aqueous medium.This method is satisfactory when Te2- is required to attack at primary carbon site of a glycidyl sulfonate.In cases where Te2- is required to attack a secondary carbon site, reduction of the tellurium must be done with NaBH4 or LiEt3BH.Elemental tellurium is precipitated during the course of the reactions and can be recovered and reused.
- Dittmer, Donald C.,Discordia, Robert P.,Zhang, Yanzhi,Murphy, Christopher K.,Kumar, Archana,et al.
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p. 718 - 731
(2007/10/02)
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- Reduction of β-ketoalkyl 2-(1-dimethylaminoethyl)phenyl sulfoxides: Synthesis of (-)-matsutakeol
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Five β-ketoalkyl 2-(1-dimethylaminoethyl)phenyl sulfoxides (2a-e) were prepared by lithiation at the α-methyl hydrogen to the sulfoxide group of N,N-dimethyl-1-(2-methylsulfinylphenyl)ethylamine (1), followed by condensation with esters. The reduction of 2a-e gave two kinds of β-hydroxysulfoxides (3a-e and 4a-e), whose structures were determined by transforming 4a to naturally occurring (-)-matsutakeol. The results on the diastereoselectivity of this reduction and the 1H-NMR spectral behavior of the α-hydrogens to the sulfoxide group were different from those found in the case of reduction of β-ketoalkyl tolyl sulfoxides.
- Shimazaki,Ichihara,Goto,Ohta
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p. 3072 - 3075
(2007/10/02)
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- A Convergent Synthesis of (R)- and (S)-3-Octanol and (2S,3S)-Octanediol, Pheromone Components of Myrmecine Ants and The Grape Borer.
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A practical and simple synthesis of the title pheromones has been developed.Use of Sharpless' epoxidation under kinetic control and a simple chiral inversion of a secondary carbinol led to the synthesis of both pheromones using the same starting achiral synthon(III) through a convergent approach.
- Chattopadhyay, Subrata,Mamdapur, Vasant R.,Chadha, Mohindra S.
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p. 1818 - 1823
(2007/10/02)
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- Hormone-like Action of 3-Octanol and 1-Octen-3-ol from Botrytis cinerea on the Pine Wood Nematode, Bursaphelenchus xylophilus
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Hormone-like substances corresponding to β-myrcene from pine trees were found from Botrytis cinerea, on which the pine wood nematode multiplied very rapidly.The hormone-like substances of B. cinerea were identified as 3-octanol and 1-octen-3-ol.The racemates and optically active compounds of these alcohols exhibited attracting, molting and multiplication activities similar to β-myrcene.These compounds may play an important role in the growth of the pine wood nematode.
- Matsumori, Kunihiko,Izumi, Susumu,Watanabe, Hiroyasu
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p. 1777 - 1782
(2007/10/02)
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- ENANTIOSELECTIVE SYNTHESIS OF SEC-ALLYLALCOHOLS BY CATALYTIC ASYMMETRIC ADDITION OF DIVINYLZINC TO ALDEHYDES.
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Readily available chiral tridentate ligand 8 catalyzes the highly Si-face selective addition of diethyl-, di-n-propylzinc and, more significantly, of divinylzinc to aromatic and aliphatic aldehydes whereas bidentate ligands 11 and 12 exert a topologically reversed catalytic bias.
- Oppolzer, Wolfgang,Radinov, Rumen N.
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p. 5645 - 5648
(2007/10/02)
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