- Catalytic ferrier rearrangement of unsaturated nucleosides
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The attempted intermolecular addition of malonyl radicals to 1',2'- unsaturated nucleosides has led to the unexpected formation of furanones. Thus, only catalytic amounts of ceric(IV) ammonium nitrate (CAN), induce a Ferrier rearrangement. The unsaturated lactone was isolated in good yield and can serve as a precursor for the synthesis of optically active products.
- Linker, Torsten,Sommermann, Thomas,Gimisis, Thanasis,Chatgilialoglu, Chryssostomos
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- Unconventional Fragment Usage Enables a Concise Total Synthesis of (-)-Callyspongiolide
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An asymmetric synthesis of (-)-callyspongiolide is described. The route builds the macrolide domain atypically from a disaccharide and a monoterpene without passing through a seco-acid. Chiral iridium catalysis selectively joins fragments. Subsequent degradation of an imbedded butyrolactone via perhemiketal fragmentation affords a stereo- and regio-defined homoallylic alcohol that is engaged directly in a carbonylative macrolactonization. Further elaboration of the polyunsaturated appendage provides the natural product in a particularly direct and flexible manner.
- Manoni, Francesco,Rumo, Corentin,Li, Liubo,Harran, Patrick G.
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- Synthesis and antiviral activity of the cyclopropano homolog of 2,3- didehydro-2,3-dideoxythymidine
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2,3-Didehydro-2,3-dideoxythymidine is among the nucleoside analogs which have been shown to be clinically useful as anti-HIV agents. Its 2,3- cyclopropano analog has now been synthesized and evaluated. However, the title compound is inactive against HIV.
- Sard
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- A domino ring-closing metathesis as a key-step in the synthesis of chiral lactones from D-mannitol
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Chiral lactones were synthesized in six steps from D-mannitol. The key-step was a domino ring-closing metathesis reaction leading to the symmetric cleavage of a D-mannitol triene derivative and to the formation of two molecules of the desired lactone.
- Nay, Bastien,Gaboriaud-Kolar, Nicolas,Bodo, Bernard
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- A facile entry to bicyclic systems from L-glutamic acid
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An efficient synthesis of bicyclic heterocycles has been realized from L-glutamic acid. The key step is the construction of the pyrrole ring in a single step, using tosylmethyl isocyanide (TosMIC) methodology. Structures of reaction intermediates and final products were investigated using density functional theory calculations.
- Frieman, Bryan A.,Bock, Charles W.,Bhat, Krishna L.
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- AN EFFICIENT TOTAL SYNTHESIS OF 3'-AZIDO-3'-DEOXYTHYMIDINE (AZT) AND 3'-AZIDO-2',3'-DIDEOXYURIDINE (AZDDU, CS-87) FROM D-MANNITOL
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An efficient stereoselective total synthesis of 3'-azido-3'deoxythymidine (AZT) and 3'-azido-2',3'-dideoxyuridine (AZDDU, CS-87) from readily available and inexpensive starting material, D-mannitol has been achieved.
- Chu, Chung K.,Beach, J. Warren,Ullas, Giliyar V.,Kosugi, Yoshiyuki
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- The use of d-mannitol-derived C2-symmetric trienes in tandem metathesis reactions towards valuable lactones
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Chiral lactones were synthesized from d-mannitol. C2-symmetric triene precursors were constructed with a central relay-olefin allowing the key domino ring-closing metathesis to be achieved. It led to the symmetrical cleavage of the substrate and to the formation of 2 mol of the desired 5- or 6-membered lactone. Attempts to form 7-membered lactones thus far only led to 14-membered macrodiolides instead.
- Riache, Nassima,Blond, Alain,Nay, Bastien
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- High-Yielding Diastereoselective syn-Dihydroxylation of Protected HBO: An Access to D-(+)-Ribono-1,4-lactone and 5-O-Protected Analogues
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A diastereoselective chemoenzymatic synthetic pathway to D-(+)-ribono-1,4-lactone, a versatile chiral sugar derivative widely used for the synthesis of various natural products, has been designed from cellulose-based levoglucosenone (LGO). This route involves a sustainable Baeyer-Villiger oxidation of LGO to produce enantiopure (S)-γ-hydroxymethyl-α,β-butenolide (HBO) that is further functionalized with various protecting groups to provide 5-O-protected γ-hydroxymethyl-α,β-butenolides. The latter then undergo a diastereoselective and high-yielding syn-dihydroxylation of the α,β-unsaturated lactone moiety followed by a deprotection step to give D-(+)-ribono-1,4-lactone. Through this 4-step synthetic route from LGO, D-(+)-ribono-1,4-lactone is obtained with d.r. varying from 82:18 to 97:3 and in overall yields between 32 and 41 % depending on the protecting group used. Moreover, valuable synthetic intermediates 5-O-tert-butyldimethylsilyl-, 5-O-tert-butyldiphenylsilyl- as well as 5-O-benzyl-ribono-1,4-lactones are obtained in 3 steps from LGO in 58, 61 and 40 %, respectively.
- Moreaux, Maxime,Bonneau, Guillaume,Peru, Aurélien,Brunissen, Fanny,Janvier, Marine,Haudrechy, Arnaud,Allais, Florent
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- Process for Preparing Beraprost Intermediate
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The present invention relates to a method of producing an intermediate necessary for the production of 314d isomer of beraprost in a high yield and in mild reaction conditions. According to the present invention, the method can produce a compound of chemical formula 3 in a high yield, which is a major intermediate necessary for the production of 314d isomer of beraprost, in mild reaction conditions.COPYRIGHT KIPO 2017
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Paragraph 0160; 0161
(2018/01/05)
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- Cycloaddition and one-carbon homologation studies in the synthesis of advanced iridoid precursors
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A Diels-Alder cycloaddition approach to the sweroside aglycone intermediate of iridoids was explored using silylated butenolides and levoglucosenone as dienophiles under both Lewis acid and thermal conditions. Results of this study reveal no evidence that
- Stevens, Anne T.,Caira, Mino R.,Bull, James R.,Chibale, Kelly
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supporting information; experimental part
p. 3527 - 3536
(2010/01/06)
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- METHOD OF PREPARING (3R, 3aS, 6aR) -3- HYDROXYHEXAHYDROFURO [2, 3-b] FURAN AND RELATED COMPOUNDS
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A method of synthesizing (3R, 3aS, 6aR) -3- hydroxyhexahydrofuro [2, 3-b] furan (I), and related compounds, in high yield and high enantiomeric selectivity is disclosed. Also disclosed is a method of manufacturing (5S) -5-(benzyloxymethyl) -5H-furan-2-one.
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- Stereoselective photochemical 1,3-dioxolane addition to 5-alkoxymethyl-2(5H)-furanone: Synthesis of bis-tetrahydrofuranyl ligand for HIV protease inhibitor UIC-94017 (TMC-114)
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A convenient synthesis of (3R,3aS,6aR)-3-hydroxyhexahydrofuro[2,3-b]furan, a high-affinity non-peptidal ligand for HIV protease inhibitor UIC-94017, is described. This inhibitor is undergoing advanced clinical trials. The synthesis utilizes a novel stereoselective photochemical 1,3-dioxolane addition to 5(S)-benzyloxymethyl-2(5H)-furanone as the key step. The requisite furanone derivative was prepared in high enantiomeric excess by an immobilized lipase-catalyzed selective acylation of (±)-1-(benzyloxy)-3-buten-2-ol and a ring-closing olefin metathesis with Grubbs' catalyst. Optically active bis-THF was converted to protease inhibitor 2 (UIC-94017).
- Ghosh, Arun K.,Leshchenko, Sofiya,Noetzel, Marcus
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p. 7822 - 7829
(2007/10/03)
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- Synthesis of Optically Active Butenolides and γ-Lactones by the Sharpless Asymmetric Dihydroxylation of β,γ-Unsaturated Carboxylic Esters
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Keywords: asymmetric synthesis; butenolides; dihydroxylations; furanones; lactones
- Harcken, Christian,Brueckner, Reinhard
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p. 2750 - 2752
(2007/10/03)
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- A synthetic route to 3-C-alkyl (or 3-C-phenyl-) 2,3-dideoxy-D-erythro- pentono-1,4-lactones: Intermediates in the synthesis of 2(3H)-furanones
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A series of 3-C-alkyl- (and 3-C-phenyl-) 2,3-dideoxy-D-erythro-pentono- 1,4-lactones, compounds which are important in the synthesis of modified nucleosides and antibiotic sugars, were synthesized from D-ribonolactone. By a route that proceeded via 5-O-pr
- Raveendranath,Blazis,Agyei-Aye,Hebbler,Gentile,Hawkins,Johnson,Baker
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p. 207 - 223
(2007/10/02)
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- Stereoselective synthesis of 3-azido-2,3-dideoxy-D-ribose derivatives and its utilization for the synthesis of anti-HIV nucleosides [1]
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Detail account of the synthesis of 3'-azido nucleosides utilizing 3- azido-2,3-dideoxy-D-ribose derivative 7 as the key intermediate was described. The key intermediate 7 was synthesized from D-mannitol in 8 steps in a preparative scale. The Michael reaction of the azide group with α,β- unsaturated-γ-butyrolactone 4 was affected by the steric bulkiness of the substituent at the 5-O position. A bulky t-butyldiphenylsilyl substitution at 5-O gave almost exclusively the α-azido adduct 5b, while unsubstitution at 5-O produced I:1 mixture of α-and β-adducts. The ratio of α to β anomers in the condensation between azido acetate 7a and pyrimidine bases for the preparation of AZT and AZDU was greatly influenced by the solvent and the Lewis acid catalyst used. In the synthesis of 12(AZDU, CS-87), the combination of dichloroethane and trimethylsilyl triflate gave an optimal result, while in the case of 14(AZT), various conditions gave similar ratio of α,β anomers. The azido intermediate 7b was also utilized for the synthesis of several 3'-azido purine-like nucleosides 16-27. The glycosylation was also affected by the Lewis acid catalyst. Boron trifluoride etherate gave the desired N1-glycosylated compounds in which the α-anomer was major, but other catalysts such as trimethylsilyl triflate or stannic chloride produced N2-glycosylated compounds as the major products. The newly synthesized purine-like compounds have been tested against HIV, however, none of them showed any significant activity.
- Jeong,Beach,Chu
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p. 1445 - 1452
(2007/10/02)
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- A NEW SYNTHESIS OF (S)-5-HYDROXYMETHYL-2(5H)-FURANONE - A MULTIPURPOSE SYNTHON
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The multipurpose chiral synthons (S)-5-hydroxymethyl-2(5H)-furanone and its tert-butyldimethylsilyl ether were synthesized from 2,3-O-isopropylidene-D-glyceraldehyde in four or five stages through derivatives of 2-deoxy-D-ribonolactone.
- Danilova, G. A.,Mel'nikova, V. I.,Pivnitskii, K. K.
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p. 1905 - 1908
(2007/10/02)
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- A Short Synthesis of (S)-5-Hydroxy-2-penten-4-olide from D-Mannitol via 2,3-O-Isopropylidene-D-glyceraldehyde
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(S)-5-Hydroxy-2-penten-4-olide (5) was synthesized in three steps starting from D-mannitol bis(acetonide) (1), via D-glyceraldehyde acetonide (2) by Z-selective Wittig reaction, acid-catalyzed lactonization and crystallization with a total yield of 40percent.
- Haefele, Brigitte,Jaeger, Volker
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- EFFICIENT SYNTHESIS OF (S)-5-HYDROXYMETHYL-5(H)-FURAN-2-ONE FROM D-MANNITOL
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Chiral synthons - (S)-5-hydroxymethyl-5(H)-furan-2-one and its t-butyldimethylsilyl ether - were synthsized from D-mannitol in 6-7 steps via 2-desoxy-D-ribonolactone derivatives.
- Danilova, G. A.,Mel'nikova, V. I.,Pivnitsky, K. K.
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p. 2489 - 2490
(2007/10/02)
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