A New Chiral Synthesis of Naturally Occurring (-)-(S)-4-Hydroxy-2-pyrrolidinone

4-Hydroxy-2-pyrrolidinoneIisanattractivesimplemolecule.First,ithasservedasakeyintermediateinthesynthesis'ofoxiracetam,adrugusefulforimprovinglearningandmemory.Second,IcanbeeasilytransformedintoantiepilepticandhypotensivedrugGABOB',andhypolipidemicagentcarnitine'.Third,(-)-4-hydroxy-2-pyrro-lidinoneIhasbeenisolated'fromthetoadstollAmanitamuscaria.Itsabsoluteconfigurationhasbeenerroneouslyassigned'as(R).ThefirstchiralsynthesisofthiscompoundhasbeenreportedbyPifferi#.However,notuntil1984didi…     

An alternative stereoselective total synthesis of (-)-pyrenophorol

The total synthesis of 16-membered C₂–Symmetric dilactone (-)-Pyrenophorol was accomplished starting from commercially available (S)-epoxide prepared by hydrolytic kinetic resolution of (±) – epoxide with key steps of Grignard reaction, Swern oxidation, Wittig reaction and cyclization was achieved by intermolecular Mitsunobu cyclization. The synthesis of (-)-Pyrenophorol accomplished from cheaply available starting material, easily work-up procedures and reduction of cost in industrial process were major advantages of this route.     

药物中间体(S)-3-羟基四氢呋喃的合成研究

(S)-3-hydroxy-tetrahydrofuran was synthesized from L-malic acid by esterification,reduction,cyclization.The chemical structures of the target compound was identified by element analysis,IR,NMR andMS spectra.The total yield and the purity of the product were 41% and 99.2%,the optical purity was 95.8%.This optimal synthetic procedure with lower cost and mild reaction conditions be worthy to have a further pilot manufacture.     

(4S)-4-羧基杂氮硅三环的合成

利用L-N,N-双(β-羟乙基)丝氨酸及L-N,N-双(β-羟乙基)苏氨酸与三乙氧基硅烷或氯烷基三乙氧基硅烷反应合成了具有手性的(4S)-4-羧基杂氮硅三环(1～5),并运用IR、~1HNMR、EI-MS等手段表征了结构。证据显示存在着贯穿笼状结构的N→Si配键。     

A Practical Synthesis of (S)-(+)-2-(6-methoxyl-2-naphthyl) propionic Acid

a-Arylpropionic acids are an important class of non-steroidal anti-inflammatory agents1,2. The therapeutic efficacy of this class of drugs is well demonstrated by the introduction and extensive use of more than a dozen compounds exemplified by ibuprofen, naproxen, ketoprofen and flurbiprofen etc. However, in recent years the use of enantiomerical pure drugs in chemotherapy is becoming almost mandatory for enhancing specificity of drug action and reducing the toxicity. This awareness led to …     

(+)-(1S,2S,5R)-8-联苯薄荷醇的合成

以(R)-( )-pu legone为起始原料,经1,4-加成,还原两步反应合成了手性辅助试剂( )-(1S,2S,5R)-8-联苯薄荷醇及其差向异构体(-)-(1R,2S,5R)-8-联苯薄荷醇,总产率95%。其结构经1H NMR,13C NMR,IR,MS和X-射线衍射仪表征。     

Palladium-catalyzed stereoselective synthesis of 3-(aminomethylene)-oxindoles

An efficient palladium-catalyzed protocol for the stereoselective synthesis of 3-(aminoarylmethylene)-oxindoles has been developed. In this approach, Ugi-4-component reaction adducts were used as starting materials for carbopalladative cyclization-Buchwald reaction sequences.     

A facile stereoselective synthesis of (E)-α-silylvinylstannanes via hydromagnesiation of alkynylsilanes

(E)-α-Silylvinylstannanes have been synthesized by the hydromagnesiation reaction of alkynylsilanes, followed by the reaction with trialkylstannyl chlorides. (E)-α-Silylvinylstannanes can undergo the cross-coupling reaction with aryl iodides in the presence of a catalytic amounts of Pd(PPh₃)₄ and CuI to afford (Z)-1,2-disubstituted vinylsilanes in good yields.     

Synthesis of the Juvenoid (S)-(+)-Hydroprene from L-(-)-Menthol

The versatile chiral synthon methyl (R)-5,5-dimethoxy-3-methylpentanoate has been prepared for the first time via ozonolytic decyclization of (R)-4-menthenone, which is available from L-(-)-menthol. The optically pure juvenoid (S)-(+)-hydroprene can be prepared from the synthon     

Synthesis of (4S)-4-Carboxyl-1-oxoperoxovanatranes

Anumberofvanadiumhaloperoxidasehavebeenisolatedfrommarinealgaeandlichen'andarethoughttobeinvolvedintheproductionofalargenumberofhalogenatedorganicsinvivo2.Theactivesiteisshowntoconsistofanoxovanadium(V)withN/Odonors3-5.Somevanatranecompounds(2.8.9-trioxa-5-aza-l-vanabicycl[3.3.3]un-decanes)havebeencharacterizedasfunctionalmodelfromthevanadiumhaloperoxidasesenZymes'.Infact,manyclassesofmetalatranecompoundshavebeensynthesizedandstudiedbecauseoftheirspecificstructureandbiologicalactivity'.Recen…     

Synthesis of （S）-2-（3-Arylacrylamido）-3-{4-[2-（5-methyl-2-phenyloxazol-4-yl）ethoxy]phenyl}propanoic Acids

The synthesis of （S）-2-（3-arylacrylamido）-3-{4-[2-（5-methyl-2-phenyloxazol-4-yl）etho- xy]phenyl}propanoic acids is described. Their structures were confirmed by ^1H-NMR.     

(S)-3-羟基四氢呋喃的合成研究进展

综述了(S)-3-羟基四氢呋喃制备方法的研究现状,重点阐述了三种合成方法：（1）手性底物合成法;（2）手性催化剂不对称合成法;（3）酶催化不对称合成法。分析了不同制备方法的优劣,并对其未来发展进行了展望。参考文献45篇。     

(S)-(4-溴-2-甲苯)(3-甲基吗啉)甲酮的合成

以(S)-2-氨基丙醇和氯乙酰氯为起始原料,经酰化和环合反应制得(S)-5-甲基吗啉-3-酮（4）; 4经还原制得(S)-3-甲基吗啉(5); 5与4-溴-2-甲基苯甲酸酰化缩合合成了(S)-(4-溴2-甲基苯基)(3-甲基吗啉)-甲酮,总收率57%,其结构经¹H NMR 和 ¹³C NMR确证。     

Palladium catalyzed stereoselective synthesis of 3-(anilinoarylmethylene)-2-oxindoles as Hesperadin analogoues

Potentially bioactive 3-(anilinoarylmethylene)-2-oxindoles as Hesperadin analogoues have been synthesized via a two-step procedure: (a) an Ugi-4MCR and (b) reaction of the Ugi adduct with aniline in the presence of a palladium catalyst via domino Heck/Buchwald reaction. In all cases, a single isomer with the Z-configuration was obtained in good to high yields.     

(2S)-(+)-2-溴-1-(6'-甲氧基-2'-萘基)丙-1-酮的不对称合成

以(2R,3R)-酒石酸二甲酯为手性辅助剂,6-甲氧基-2-丙酰基萘经缩酮化、溴化铜不对称溴化、水解等反应合成了(2S)-2-溴-1-(6'-甲氧基-2'-萘基)丙-1-酮。总收率94%。     

Synthesis and Crystal Structure of （2S,5S）-1-Aza-2-（2-pyridyl）-3-oxa-4,4-diphenylbicyclo [3.3.0] Octane

1 INTRODUCTION The catalytic asymmetric synthesis has been a challenging subject in organic synthesis. The deve- lopment of efficient enantioselective catalysts appli- cable to a wide range of carbon-carbon bond form- ing reactions represents a pivotal …     

具有抗HIV活性的螺环缩酮类化合物合成研究: Didemnaketals C(1)～C(8)片段 的合成

以天然薄荷酮为原料,立体选择性地合成了具有抗艾滋病活性的化合物DidemnaketalsAC(1)～C(8)片段,(3S,5R,6S)-3-甲基-5,6-丙酮化物-7-氧代-辛酸甲酯及其6R异构体。     

Synthesis and Crystal Structure of (1S)-1,1'-Bis{[N-ethyl-N-(1-methylethyl)-amino]-carbonyl}-2-(hydroxydiphenylmethyl)-ferrocene

The title complex, (1S)-1,1'-bis{[N-ethyl-N-(1-methylethyl)-amino]carbonyl}-2- (hydroxyldiphenylmethyl)-ferrocene ([Fe(C24H22NO2)(C11H16NO)]2·H2O, Mr = 1207.13), was synthesized via (-)-Sparteine-mediated enantioselective directed ortho-lithiation of 1,1'-bis{[N- ethyl-N-(1-methylethyl)-amino]carbonyl}-2-(hydroxydiphenylmethyl)-ferrocene. The structure of the title compound was determined by X-ray single-crystal diffraction. The crystal belongs to the orthorhombic system, space group P212121, with a = 10.26...     

A simple and practical method for the stereoselective synthesis of (Z)-1-iodo-1-alkenes from 1,1-diiodo-1-alkenes

Treatment of the 1,1-diiodo-1-alkenes 8, prepared from the corresponding aldehydes with CI₄/PPh₃, with ZnCu/AcOH in THF-MeOH gave the (Z)-1-iodo-1-alkenes 9, selectively, in good yields.     

(S)-(+)-2,2-二甲基环丙烷甲酰胺的不对称合成

以环己二胺作为手性源,与3,5-二叔丁基水杨醛经缩合反应制得Salen配体(R,R)-N,N'-二(3,5-二叔丁基水杨醛)-1,2-环己二胺(6);甘氨酸乙酯盐酸盐经重氮化和6与三氟甲烷磺酸亚铜催化的不对称环丙烷化反应制得(S)-(+)-2,2-二甲基环丙烷甲酸乙酯(9);9经水解、酰氯化和氨解反应合成了(S)-(+)-2,2-二甲基环丙烷甲酰胺,ee值82%,总收率55.4%,其结构经1H NMR和IR确证。