- A convenient synthesis of the enantiomerically pure (S)-2,4-dihydroxybutyl-4-hydroxybenzoate using hydrolytic kinetic resolution
-
(S)-2,4-Dihydroxybutyl-4-hydroxybenzoate was prepared in an extremely simple and practical way with high enantiomeric excess (99% ee) using Jacobsen’s Hydrolytic Kinetic Resolution technique as a key step and source of chirality.
- More, Namita A.,Jadhao, Nitin L.,Garud, Dinesh R.,Gajbhiye, Jayant M.
-
p. 2093 - 2098
(2018/07/15)
-
- SILVESTROL ANTIBODY-DRUG CONJUGATES AND METHODS OF USE
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The invention relates generally to a silvestrol molecule activated with a leaving group. The invention further relates generally to an antibody-drug conjugate comprising an antibody conjugated by a linker to one or more silvestrol drug moieties and methods of treatment.
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- Intramolecular thermal stepwise [2 + 2] cycloadditions: Investigation of a stereoselective synthesis of [n.2.0]-bicyclolactones
-
Fused cyclobutanes are found in a range of natural products and formation of these motifs in a straightforward and easy manner represents an interesting synthetic challenge. To this end we investigated an intramolecular variant of the thermal enamine [2 + 2] cyclisation, developing a diastereoselective intramolecular enamine [2 + 2] cyclisation furnishing δ lactone and lactam fused cyclobutenes in good yield and excellent diastereoselectivity.
- Throup, Adam,Patterson, Laurence H.,Sheldrake, Helen M.
-
supporting information
p. 9554 - 9559
(2016/10/22)
-
- Carbohydrate-Catalyzed Enantioselective Alkene Diboration: Enhanced Reactivity of 1,2-Bonded Diboron Complexes
-
Catalytic enantioselective diboration of alkenes is accomplished with readily available carbohydrate-derived catalysts. Mechanistic experiments suggest the intermediacy of 1,2-bonded diboronates.
- Fang, Lichao,Yan, Lu,Haeffner, Fredrik,Morken, James P.
-
supporting information
p. 2508 - 2511
(2016/03/12)
-
- A concise stereoselective total synthesis of diplodialide C
-
An asymmetric total synthesis of diplodialide C has been achieved starting from commercially available homoallylic alcohol. Regioselective opening of the chiral epoxide, cross-metathesis reaction, and Yamaguchi macrolactonization were used as the key step
- Pratapareddy, Bommareddy,Sreenivasulu, Reddymasu,Hatti, Islavathu,Venkata Basaveswara Rao, Mandava,Raju, Rudraraju Ramesh
-
p. 1921 - 1926
(2015/10/29)
-
- Asymmetric Oxy-Michael Addition to γ-Hydroxy-α,β-Unsaturated Carbonyls Using Formaldehyde as an Oxygen-Centered Nucleophile
-
Formaldehyde was utilized as an oxygen-centered nucleophile in an asymmetric oxy-Michael addition to γ-hydroxy-α,β-unsaturated carbonyl compounds using bifunctional organocatalysts through hemiacetal intermediates. The cyclic acetal product could be further transformed into β-hydroxycarbonyl compounds, useful synthetic intermediates leading to various important target molecules. As such, this method is an example of a novel formal asymmetric hydration of α,β-unsaturated carbonyl compounds.
- Yoneda, Naoki,Hotta, Ayano,Asano, Keisuke,Matsubara, Seijiro
-
p. 6264 - 6266
(2015/02/19)
-
- A new enantioselective synthesis of the anticonvulsant drug pregabalin (lyrica) based on a hydrolytic kinetic resolution method
-
A practical and efficient enantioselective synthesis of the anticonvulsant drug pregabalin is described for the first time using Jacobsen's hydrolytic kinetic resolution of a terminal epoxide as a key step and a source of chirality.
- Mujahid, Mohammad,Muthukrishnan, Murugan
-
p. 965 - 969
(2014/01/06)
-
- MATRIX METALLOPROTEINASE INHIBITORS
-
The present invention relates to methyl sulfonamides and N-formamides derivatives of formula (I) and to processes for their syntheses. The invention also relates to pharmacological compositions containing these derivatives and methods of treating asthma, rheumatoid arthritis, COPD, rhinitis, osteoarthritis, psoriatie arthritis, psoriasis, pulmonary fibrosis, pulmonary inflammation, acute respiratory distress syndrome, perodontitis, multiple sclerosis, gingivitis, atherosclerosis, dry eye, neointimal proliferation which leads to restenosis and ischemic heart failure, stroke, renal disease, tumor metastasis, and other inflammatory disorders characterized by over expression and over activation of an matrix metalloproteinase using the compounds.
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- Microbial oxidation of 1,2-diols bearing a substituent with an oxyfunctional group: Preparation of optically active 1,2-diols and α-hydroxy ketones
-
The preparation of optically active 1,2-diols bearing a substituent with a benzyloxy group at the terminus has been achieved by microbial enantioselective oxidation of the racemic compounds. In the screening test, Ochrobactrum sp. MU2293 was selected as the best strain to perform the enantioselective oxidation of (±)-4-benzyloxybutane-1,2-diol to give the corresponding 4-benzyloxy-1-hydroxybutan-2-one and the remaining (R)-diol with a high ee. This microbial oxidation was applicable to other substrates bearing a substituent with a different carbon number. On the other hand, Bacillus sp. MU2289 catalyzed the oxidation of the 1,2-diols to afford the corresponding α-hydroxy ketones and the (S)-diols as the remaining substrates with the opposite absolute configuration.
- Matsumoto, Kazutsugu,Hashimoto, Key,Sakuragi, Mari,Kusunoki, Ayumi,Nogawa, Masaki
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scheme or table
p. 536 - 539
(2012/06/01)
-
- Stereoselective synthesis and biological evaluation of (R)-rugulactone, (6R)-((4R)-hydroxy-6-phenyl-hex-2-enyl)-5,6-dihydro-pyran-2-one and its 4S epimer
-
A simple and highly efficient synthetic route has been developed for synthesis of (R)-rugulactone (1a), (6R)-((4R)-hydroxy-6-phenyl-hex-2-enyl)-5,6- dihydro-pyran-2-one (1b) and its 4S epimer 1c by employing proline-catalyzed α-aminooxylation, Sharpless epoxidation, Mitsunobu reaction as chirality introuducing steps. The antibacterial and antifungal activity of the compounds 1a, 1b and 1c were evaluated. 1a and 1b showed better antibacterial activity against Pseudomonas aeroginosa (MIC =12.5 μg/ml for 1a, 25 μg/ml for 1b) Klebsiella pneumonia (MIC =25 μg/ml for 1a). Compounds (1a, 1b, 1c) exhibited good to moderate antifungal activity.
- Reddy, D. Kumar,Shekhar,Prabhakar,Chinna Babu,Siddhardha,Murthy,Venkateswarlu
-
experimental part
p. 4657 - 4663
(2010/10/19)
-
- Ring-conformer effects of the cyclopropyl group: First use of trans-(2r,3r)-cyclopropanecarbaldehydes as electrophiles in diastereoselective baylisihillman reaction
-
trans-(2R,3R)-Cyclopropanecarbaldehydes are used as novel electrophiles in the Baylis-Hillman reaction to afford adducts in good yields (75-85%) and diastereoselectivities (60-90%).
- Krishna, Palakodety Radha,Kishore,Reddy, P. Srinivas
-
scheme or table
p. 2605 - 2608
(2010/03/03)
-
- Mechanistic investigation of the Candida albicans CCT 0776 stereoinversion system and application to obtain enantiopure secondary alcohols
-
Phenylethanol deracemization with Candida albicans CCT 0776 whole cells yields the (R)-enantiomer in over 99% enantiomeric excess and 98% yield. The deracemization process involves, in the first step, a fast, highly (S)-selective oxidation (NADP and O2 dependent) and, in the second step, a slower partially (S)-selective reduction (NADH dependent) of the intermediate ketone. The process was extended to other 2-alkanols, 1,2-diols and 1,3-diols and, with the exception of 1,3-diol (unreactive), the enantiomeric excess and yield of the deracemization were about 99% and 62-98%, respectively.
- Mantovani, Simone M.,Angolini, Celio F.F.,Marsaioli, Anita J.
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experimental part
p. 2635 - 2638
(2010/03/30)
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- An efficient and stereoselective route to 1-deoxy-5-hydroxy sphingosine analogues
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A short and efficient synthesis of 1-deoxy-5-hydroxy sphingolipid is described. The key steps involved are a Jacobsen hydrolytic kinetic resolution (HKR) and Shibasaki's asymmetric Henry reaction.
- Saikia, Partha Pratim,Goswami, Abhishek,Baishya, Gakul,Barua, Nabin C.
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scheme or table
p. 1328 - 1330
(2009/07/17)
-
- Stereodivergent methodology for the synthesis of complex pyrrolidines
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The intramolecular reaction of oxime ethers and cyclopropane diesters results in the diastereoselective formation of substituted pyrrolo- isoxazolidines which serve as precursors to the ubiquitous pyrrolidine motif. A simple reversal of addition order of catalyst and substrate results in formation of two discrete diastereomers in a highly selective and predictable manner. The adducts are prepared in excellent yields from either enantiomer of an alkoxyamino-tethered cyclopropanediester, allowing efficient access to highly substituted homochiral pyrrolidines.
- Jackson, Stephen K.,Karadeolian, Avedis,Driega, Alex B.,Kerr, Michael A.
-
p. 4196 - 4201
(2008/12/20)
-
- The first stereoselective and the total synthesis of Leiocarpin C and total synthesis of (+)-Goniodiol
-
The synthesis of the styryl lactone Leiocarpin C has been achieved in a highly stereoselective manner using Jacobsen's kinetic resolution, Sharpless asymmetric epoxidation and Sharpless asymmetric dihydroxylation as key steps. This is the first total synthesis of Leiocarpin C, and thus establishes for the first time the absolute stereochemistry of this natural product.
- Yadav,Premalatha,Harshavardhan,Subba Reddy
-
scheme or table
p. 6765 - 6767
(2009/04/11)
-
- An efficient organocatalytic route to the atorvastatin side-chain
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An organocatalytic route to the synthesis of the atorvastatin side-chain, a building block present in the statin family, is described using l-proline-catalyzed α-aminooxylation of an aldehyde. The method also employs an iodine-induced intramolecular electrophilic cyclization of a carbonate to produce the iodocarbonate in a highly diastereoselective manner.
- George, Shyla,Sudalai, Arumugam
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p. 8544 - 8546
(2008/09/17)
-
- Enantioselective synthesis of tarchonanthuslactone using proline-catalyzed asymmetric α-aminooxylation
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A practical enantioselective synthesis of tarchonanthuslactone 1, an important natural product with a polyol unit, is described. The sequence of synthetic reactions involves proline-catalyzed α-aminooxylation and iodine-induced electrophilic cyclization as the chiral inducing steps.
- George, Shyla,Sudalai, Arumugam
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p. 975 - 981
(2008/02/03)
-
- "Cassette" in situ enzymatic screening identifies complementary chiral scaffolds for hydrolytic kinetic resolution across a range of epoxides
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(Figure Presented) Put the cassette in: An in situ enzymatic screen can give real-time estimates of the sense and magnitude of enantioselectivity across more than one substrate. Screening identified CoIII-salen catalysts with β-pinene- and α-naphthylalanine-derived chiral scaffolds with broad, yet complementary, substrate specificities. ADH = alcohol dehydrogenase, HL = horse liver, LK = Lactobacillus kefir, salen = (salicylidene) ethylenediamine.
- Dey, Sangeeta,Powell, Douglas R.,Hu, Chunhua,Berkowitz, David B.
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p. 7010 - 7014
(2008/09/17)
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- An efficient, highly enantioenriched route to L-carnitine and α-lipoic acid via hydrolytic kinetic resolution
-
A general and practical approach for the synthesis of C-4 chiral building blocks using Jacobsen's hydrolytic kinetic resolution technique to resolve terminal epoxides and diols in high enantiomeric excess and excellent yields is described. The utilization of these building blocks for the synthesis of biologically important natural products L-carnitine and α-lipoic acid is illustrated. Georg Thieme Verlag Stuttgart.
- Bose, D. Subhas,Fatima, Liyakat,Rajender, Salla
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p. 1863 - 1867
(2008/01/27)
-
- Synthesis of a potent hNK-1 receptor antagonist via an SN2 reaction of an enantiomerically pure α-alkoxy sulfonate
-
(Chemical Equation Presented) The concise synthesis of a stereochemically rich hNK-1 receptor antagonist is described. The synthesis is highlighted by an SN2 reaction of an enantiomerically pure α-alkoxy sulfonate (orthogonally protected butane triol), which was prepared by utilizing salen-mediated hydrolytic kinetic resolution technology. A stereocontrolled acetalization was employed to connect two enantiomerically pure fragments with a high degree of diastereoselectivity.
- Nelson, Todd D.,Rosen, Jonathan D.,Smitrovich, Jacqueline H.,Payack, Joseph,Craig, Bridgette,Matty, Louis,Huffman, Mark A.,McNamara, James
-
-
- Synthesis of cis- and trans-2,5-disubstituted tetrahydrofurans by a tandem dihydroxylation-SN2 cyclization sequence
-
(Chemical Equation Presented) Dihydroxylation of δ- and ε-mesyloxy α,β-unsaturated esters proceeds with in situ cyclization to afford 2,5-disubstituted and 2,3,5-trisubstituted tetrahydrofurans.
- Marshall, James A.,Sabatini, Jesse J.
-
p. 4819 - 4822
(2007/10/03)
-
- Process for producing butanetriol derivative
-
A process for preparing a butanetriol derivative of the formula (1) useful as intermediates of medicines wherein R1is the same defined below, which comprises reacting a compound of the formula (3) wherein R1and R2are the different protecting groups, and an ethylene glycol derivative in a basic condition to prepare a compound of the formula (4) or (4a) wherein R1and R2are the same defined above, and then subjecting the compound (4) or (4a) to selective deprotection reaction.
- -
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-
- Highly selective hydrolytic kinetic resolution of terminal epoxides catalyzed by chiral (salen)CoIII complexes. Practical synthesis of enantioenriched terminal epoxides and 1,2-diols
-
The hydrolytic kinetic resolution (HKR) of terminal epoxides catalyzed by chiral (salen)CoIII complex 1·OAc affords both recovered unreacted epoxide and 1,2-diol product in highly enantioenriched form. As such, the HKR provides general access to useful, highly enantioenriched chiral building blocks that are otherwise difficult to access, from inexpensive racemic materials. The reaction has several appealing features from a practical standpoint, including the use of H2O as a reactant and low loadings (0.2-2.0 mol %) of a recyclable, commercially available catalyst. In addition, the HKR displays extraordinary scope, as a wide assortment of sterically and electronically varied epoxides can be resolved to ≥ 99% ee. The corresponding 1,2-diols were produced in good-to-high enantiomeric excess using 0.45 equiv of H2O. Useful and general protocols are provided for the isolation of highly enantioenriched epoxides and diols, as well as for catalyst recovery and recycling. Selectivity factors (krel) were determined for the HKR reactions by measuring the product ee at ca. 20% conversion. In nearly all cases, krel values for the HKR exceed 50, and in several cases are well in excess of 200.
- Schaus, Scott E.,Brandes, Bridget D.,Larrow, Jay F.,Tokunaga, Makoto,Hansen, Karl B.,Gould, Alexandra E.,Furrow, Michael E.,Jacobsen, Eric N.
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p. 1307 - 1315
(2007/10/03)
-
- Studies directed toward the total synthesis of pinnatoxin A: Synthesis of the 6,5,6-dispiroketal (BCD ring) system by double hemiketal formation/hetero-Michael addition strategy
-
An efficient, highly stereoselective synthesis of the C10-C26 portion of pinnatoxin A has been achieved, wherein the key step is a highly stereoselective construction of the 6,5,6-dispiroketal (BCD ring) system by an intramolecular hetero-Michael addition of a hemiketal alkoxide reversibly formed under the influence of lithium methoxide.
- Nakamura, Seiichi,Inagaki, Jun,Kudo, Masashi,Sugimoto, Tomohiro,Obara, Kohei,Nakajima, Makoto,Hashimoto, Shunichi
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p. 10353 - 10374
(2007/10/03)
-
- An approach towards the C1-C16 fragment of antineoplastic macrolide bryostatins by kinetic resolution of a racemic terminal epoxide using Jacobsen's catalyst
-
A stereo- and enantioselective approach towards the C1-C16 fragment of bryostatins is reported using Jacobsen's catalyst for kinetic resolution of a terminal epoxide, a Horner-Wadsworth-Emmons coupling reaction and a 1,4-Michael type cyclization as key steps.
- Yadav,Bandyopadhyay,Kunwar
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p. 4907 - 4911
(2007/10/03)
-
- Synthesis of (S)- and (R)-3-hydroxyhexadecanoic acid
-
Diol (R)-(+)-3 is prepared either from the hydroxyketone 2 by reduction with fermenting baker's yeast or by hydrolysis of the dioxolane (R)-(+)-1 which is available from dimethyl D-malate as starting material. (R)-(+)-3 could be converted stereoselectively into (R)-(+)-4. Reaction of (+)-4 with dodecylmagnesium bromide yielded the alcohol (S)-(-)-5 with >99% ee. Its acetylation gave (S)-(+)-6 and hydrogenolysis gave the primary alcohol (S)-(+)-7 which could be oxidized selectively to (S)-(+)-8 wih NaIO4/RuCl3. Alkaline hydrolysis of (+)-8 yielded 3-hydroxyhexadecanoic acid (S)-(+)-9 which could be esterified to give the methyl ester (S)-(+)-10 with >99% ee. Starting with the dioxolane (S)-(-)-1, derived from dimethyl L-malate, the 3-hydroxyhexadecanoic acid (R)-(-)-10 could be synthesised via the intemediates (S)-(-)-3, (S)-(-)-4, (R)-(+)-5, (R)-(-)-6, (R)-(-)-7 and (R)-(-)-8. Copyright (C) Elsevier Science Ltd.
- Jakob, Barbara,Voss, Gundula,Gerlach, Hans
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p. 3255 - 3262
(2007/10/03)
-
- Preparation of optically active diol derivatives by the enzymatic hydrolysis of cyclic carbonates
-
A simple enzymatic method for the preparation of optically active 1,2- and 1,3-diol derivatives is disclosed. In the screening of enzymes, racemic 4-[(2-benzyloxy)ethyl]-1,3-dioxolan-2-one (1a) was enantioselectively hydrolyzed by porcine pancreas lipase (PPL) to give optically active (R)-1a and (S)-4-(benzyloxy)butane-1,2-diol (2a). The addition of 10% i-PT2O to the reaction system dramatically improved the reactivity to afford optically pure (A)-1a in 31% yield. PPL also catalyzed the hydrolysis of several five-membered cyclic carbonates with high enatioselectivity. It is noteworthy that the increment of the carbon number of the substituents reflects the drastic increase in enantioselectivity. On the other hand, the hydrolyses of six- and seven-membered cyclic carbonates were also catalyzed by PPL. In particular, the reaction of a six-membered substrate enantioselectively proceeded. This reaction afforded optically active 1,3-diol derivatives which could not be directly prepared by hitherto known methods using hydrolytic enzymes.
- Matsumoto, Kazutsugu,Fuwa, Seiji,Shimojo, Megumi,Kitajima, Hidehiko
-
p. 2977 - 2987
(2007/10/03)
-
- Highly enantioselective and regioselective catalytic dihydroxylation of homoallylic alcohol derivatives
-
The catalytic dihydroxylation of p-methoxyphenyl ethers of various homoallylic alcohols proceeds with excellent enantioselectivity and in the case of diolefins with regioselectivity due to the favorable influence of the aryl ether moiety, as predicted from a previously proposed transition-state model.
- Corey,Guzman-Perez, Angel,Noe, Mark C.
-
p. 3481 - 3484
(2007/10/02)
-
- A Difference CD Method for Determining Absolute Stereochemistry of Acyclic 1,2,4-Triols
-
A general method based on difference circular dichroic (DIF CD) spectroscopy for assigning the absolute configuration of 1,2,4-triol is presented.Four possible stereoisomers of 6-heptene-1,2,4-triol were prepared and served as models to develop the procedure.The sign of the DIF CD Cotton effect is correlated to the absolute configuration of the C2 position.
- Mori, Yuji,Furukawa, Hiroshi
-
p. 6725 - 6738
(2007/10/02)
-
- Modified Preparation Method of Trifluoromethylated Propargylic Alcohols and Its Application to Chiral 2,6-Dideoxy-6,6,6-trifluorosugars
-
Convenient generation of 3,3,3-trifluoropropynyl anion was realized from 2-bromo-3,3,3-trifluoropropene, and the anion's reaction with various electrophiles proceeded in excellent isolated yields.One of the products, 1-(benzyloxy)-6,6,6-trifluoro-4-hexyn-3-ol (4b), was further employed for the diastereoselective construction of 2,6-dideoxy-6,6,6-trifluorosugars after enzymatic optical resolution and osmium dihydroxylation of the corresponding olefins.The strongly electron-withdrawing trifluoromethyl moiety, significantly affecting the nucleophilic nature of the neighbouring functionalities, allows to ready differentiation of hydroxy groups by routine chemical transfromation, which results in the shortening of the reaction sequence.
- Yamazaki, Takashi,Mizutani, Kenji,Kitazume, Tomoya
-
p. 6046 - 6056
(2007/10/03)
-
- A NEW SYNTHETIC APPROACH TO (R)-GABOB FROM L-MALIC ACID
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A synthesis of (R)-4-amino-3-hydroxybutanoic acid, starting from L-malic acid, is reported.The synthetic approach involves an inversion of configuration of the chiral centre to obtain the correct stereochemistry, together with the protection of the 1,2-am
- Misiti, Domenico,Zappia, Giovanni,Monache, Giuliano Delle
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p. 219 - 222
(2007/10/02)
-
- Enzyme-mediated enantioselective hydrolysis of cyclic carbonates
-
The enzyme-mediated enantioselective hydrolysis of cyclic carbonates is disclosed. Racemic 4-(2-benzyloxy)ethyl-1,3-dioxolan-2-one (1a) was enantioselectively hydrolyzed by porcine pancreas lipase (PPL) to give optically active (R)-1a and (S)-4-benzyloxybutane-1,2-diol (2a). PPL also catalyzed the hydrolysis of several five-membered cyclic carbonates with high enantioselectivity.
- Matsumoto, Kazutsugu,Fuwa, Seiji,Kitajima, Hidehiko
-
p. 6499 - 6502
(2007/10/02)
-
- Novel Stereoselective Syntheses of Chiral 2,6-Dideoxy-6,6,6-trifluoro Sugars via Enzymatic Resolution of Trifluoromethylated Propynylic Alcohol
-
All stereoisomers of homochiral 2,6-dideoxy-6,6,6-trifluoro sugars are conventionally synthesized from the same optically pure CF3-containing propynylic alcohol via the novel one-pot reaction of 2-bromo-3,3,3-trifluoropropene, followed by optical resoluti
- Mizutani, Kenji,Yamazaki, Takashi,Kitazume, Tomoya
-
-
- Synthesis and catalytic properties of an acyclic analogue of hydroxy norphos
-
The synthesis of (S)-1,2-bis(diphenylphosphino)butane-4-ol 1 an acyclic analogue of hydroxy norphos is described, starting from L-ascorbic acid. Problems which arose during the cleavage of OH-protective groups in the presence of phosphino groups are discu
- Boerner, Armin,Ward, Jacques,Ruth, Wolfgang,Holz, Jens,Kless, Achim,Heller, Detlef,Kagan, Henri B.
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p. 10419 - 10430
(2007/10/02)
-
- Regioselective protection of triols to cyclic carbonates
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Regioselective protection of 1,2,3-, 1,2,4-, and 1,2,5-triols to 5- membered cyclic carbonates with triphosgene, dimethyl carbonate, or carbonyldiimidazole is described.
- Kang,Jeon,Nam,Park,Lee
-
p. 305 - 312
(2007/10/02)
-
- Synthesis and antiviral activity of 2'-substituted 9-[2- (phosphonomethoxy)ethyl]guanine analogues
-
A series of 2'-substituted derivatives of 9-[2- (phosphonomethoxy)ethyl]guanine (PMEG, 1) have been synthesized and evaluated in vitro for anti-human immunodeficiency virus (HIV) activity in the XTT assay and for anti-herpes activity in the plaque reducti
- Yu,Bronson,Yang,Patick,Alam,Brankovan,Datema,Hitchcock,Martin
-
p. 2726 - 2738
(2007/10/02)
-
- Stereocontrolled Total Synthesis of 9(R)-N-BOC-Ahda Methyl Ester
-
An efficient convergent route to the first total synthesis of 9(R)-N-BOC-Ahda methyl ester, in optically pure form, is described.
- Chakraborty, Tushar K,Hussain, Azhar K,Joshi, Subodh P
-
p. 2385 - 2388
(2007/10/02)
-
- Synthesis and Antiviral Activity of (S)-9-guanine
-
The synthesis of (S)-9-guanine (3), starting from (S)-4-(2-hydroxyethyl)-2,2-dimethyl-1,3-dioxolane (4), is described.Alkylation of trityl derivative 7 with (diethylphosphono)methyl triflate provided phosphonate 8, whi
- Kim, Choung Un,Luh, Bing Yu,Martin, John C.
-
p. 1797 - 1800
(2007/10/02)
-
- Studies related to the synthesis of pederin. Part 2. Synthesis of pederol dibenzoate and benzoylpedamide
-
Syntheses of the ring B fragments (+)-pederol dibenzoate (2) and (±)-benzoylpedamide (3) of the insect toxin pederin (1) are described. An intramolecular directed aldol condensation was used to construct the tetrahydropyran ring in (+)-pederol dibenzoate
- Willson, Timothy M.,Kocienski, Philip,Jarowicki, Krzysztof,Isaac, Kim,Hitchcock, Peter M.,Faller, Andrew,Campbell, Simon F.
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p. 1767 - 1782
(2007/10/02)
-
- SYNTHESES OF α-(R)-AND α-(S)-LIPOIC ACID FROM (S)-MALIC ACID
-
(S)-Malic acid has been converted into α-(R)-and α-(S)-lipoic acid via (R)-and (S)-(2-phenylmethoxyethyl)oxirane .The (R)-oxirane (2a) was cleaved with but-3-enylmagnesium bromide (cuprate catalysis) to give (S)-1-(phenylmethoxy)oct-7-en-3-ol (4a).This was converted into methyl (S)-6,8-dihydroxyoctanoate (5a), the di-O-methanesulphonate (6a) of which was treated with sodium sulphide and sulphur in dimethylformamide to yield methyl α-(R)-lipoate (7a), that was saponified to α-(R)-lipoic acid (1a).The (S)-oxirane (2b) was similarly converted into α-(S)-lipoic acid (1b).
- Brookes, Michael H.,Golding, Bernard T.,Hudson, Alan T.
-
-
- L-(S)-ERYTHRULOSE : THE SYNTHESYS OF (R)-1,2,4-BUTANETRIOL AND OF SOME RELATED C4 CHIRONS.
-
L-(S)-Erythrulose can easily be transformed into (R)-1,2,4-butanetriol and related C4 chiral building blocks.A formal synthesis of (-)-GABOB is presented.Also the formation of 3-methylene-1,2,4-butanetriol derivatives is described.
- Eycken, E. Van der,Wilde, H. De,Deprez, L.,Vandewalle, M.
-
p. 4759 - 4760
(2007/10/02)
-
- A (FORMAL) TOTAL SYNTHESIS OF (+)-STRIGOL, THE WITCHWEED GERMINATION FACTOR
-
A synthetic route to (+)-1 commencing from (S)-malic acid and 20 is reported.Key steps are the coupling of 20 and 15 to give 21, an intramolecular Wittig reaction (25-27), and an oxidative cyclization (28-1).
- Berlage, Ulrich,Schmidt, Juergen,Milkova, Zenka,Welzel, Peter
-
p. 3095 - 3098
(2007/10/02)
-
- A Synthesis of (+)-Milbemycin β3. The Directed Aldol Approach
-
A synthesis of (+)-milbemycin β3, is reported in which key steps are the construction of the 1,7-dioxaspiroundecane (15) by a Lewis acid-catalysed intramolecular directed aldol reaction and the use of sulphone-based olefination reactions f
- Street, Stephen D. A.,Yeates, Clive,Kocienski, Philip,Campbell, Simon F.
-
p. 1386 - 1388
(2007/10/02)
-
- SYNTHETIC STUDIES RELATED TO COMPACTIN AND MEVINOLIN: A NEW SYNTHESIS OF THE LACTONE SYSTEM.
-
(S)-Malic acid diethyl ester was converted into a precursor of the lactonic portion of compactin and mevinolin.The substance was coupled with benzyl p-tolyl sulfone and elaborated into the chiral lactone system of the natural products.
- Majewski, Marek,Clive, Derrick L. J.,Anderson, Paul C.
-
p. 2101 - 2104
(2007/10/02)
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- REGIOSELECTIVITY OF THE REACTIONS OF TRIALKYLALUMINUM REAGENTS WITH 2,3-EPOXYALCOHOLS: APPLICATION TO THE SYNTHESIS OF α-CHIRAL ALDEHYDES
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Treatment of optically active 2,3-epoxyalcohols with trialkylaluminum reagents followed by periodate cleavage constitutes a convenient synthesis of α-chiral aldehyde derivatives, especially when the branching alkyl group is methyl.
- Roush, William R.,Adam, Michael A.,Peseckis, Steven M.
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p. 1377 - 1380
(2007/10/02)
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