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Condensation of 2-methyl-1-pyrroline with chloroacetone or 3-chloro-2-butanone using LDA in THF afforded novel 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines via a peculiar reaction mechanism instead of the anticipated 2-(3-oxobutyl)-1-pyrrolines. The intermediacy of 2-(2,3-epoxy-2-methylalkyl)-1-pyrrolines in the latter transformation was demonstrated by immediate reductive epoxide ring opening utilizing lithium aluminium hydride in diethyl ether. Furthermore, 2-(3-oxobutyl)-1-pyrroline was prepared via an alternative approach through alkylation of 2-methyl-1-pyrroline with 3-chloro-2-(methoxymethyloxy)-1-propene using LDA in THF, followed by acid hydrolysis. Reduction of 2-(3-oxobutyl)-1-pyrroline by sodium borohydride in methanol afforded the corresponding 2-(3-hydroxybutyl)-1-pyrroline in good yield. 相似文献
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Arun K. Sarkar Sushama M. Pawar Khushi L. Matta 《Journal of carbohydrate chemistry》2013,32(2):269-278
ABSTRACT Synthesis of three tetrasaccharides, namely, 0-α-L-fucopyranosyl-(1→3)-0-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→3)-0-(β-D-galactopyranosyl)-(1→4)-β-D-glucopyranose (7), 0-α-L-fucopyranosyl-(1→4)-0-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→3)-0-(β-D-galactopyranosyl)-(1→4)-D-glucopyranose (9), and 0-α-L-fucopyransoyl-(1→3)-0-(2-acetamido-2-deoxy-β-D-glucopyransoyl)-(1→6)-0-(β-D-galactopyranosyl)-(1→4)-D-glucopyranose (15) has been described. Their structures have been established by 13C NMR spectroscopy. 相似文献
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Issa Yavari Mohammad R. Islami Azizollah Habibi Ahmad M. Tikdari Lona Ebrahimi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):575-583
3-Oxo-2-phenyl-butanenitrile or 3-oxo-2-phenyl-pentanenitrile undergo a smooth reaction with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine to produce highly-functionalized salt-free ylides in nearly quantitative yields. These stabilized phosphorus ylides exist as a mixture of two geometrical isomers as a result of restricted rotation around the carbon-carbon partial double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group. 相似文献
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A few compounds containing the 2-arylbenzofuran nucleus, have been isolated from plants.[1] For example,moracins A and B, egonol, homoegonol and (±)-machicendiol are well known. 相似文献
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1INTRODUCTIONInorganicsolidsupportsascatalystshavebeenwellstudied,becauseoftheirap-plicationsinorganicsynthese('~".Recently,wehavereportedtheKnoevenagelcon-densationcatalysedbyKF-Al,O,['i.Inthispaper,wediscussedthecrystalstruc-tureofthetitlecomPoundsynthesizedbythereactionof2-chlorobenzaldehydey5,5-dimethyl-1,3-cyclohexanedioneandisopropylidenemalonateinmethanolcatalyzedbyKF-Alzo,'Inordertoconfirmthestructureofthetitlecompound,theX-raycrys-tallOgraphicstudywascarriedout.2EXPER1MEN… 相似文献
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lINTR0DUCTIONThechemistryofstablephospheniumcati0n[Rl-P-R2j hasbeenextensivelyknowntl-3).Wereportedsynthesesandreactions0fthephospheniumcati0nsfeatur-ingwithanS-P-Nlinkage.(4-8)Recentlywefoundthatphospheniumion[i-Pr2N-P-Clj [AlC'j-canregiOselectivelyinsertintophenylcyclopropaneringattwocycliccarbon-carbonb0ndsadjacenttophenylgr0uptogivel-(diisopropyl)amin0-2-(p-methyl)phenyl-3-methyl-phosphetanel-oxide(1).Inordertodisclosetherelativesterelchemistry,itssinglecrystalwasobtainedfromn-he… 相似文献
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Propyl O-(α-L-rhamncpyranosyl)-(1→3)-[2,4-di-O-(2s-methylbutyryl)-α-L-rham-nopyranosyl]-(1→2)-(3-O-acetyl-β-D-glucopyranosyl)-(1→2)-β-D-fucopyranoside (1), the tetrasac-charide moiety of Tricolorin A, was synthesized in total 23 steps with a longest linear sequence of 10 steps, and overall yield of 3.7% from D-Glucose. The isomerization of the dioxolane-type berzyli-dene in the presence of NIS/AgOTf was observed. Tetrasaccharide 1 exhibited no activity against the cultured P388 cell as Tricolorin A did. 相似文献
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YU An-Guang WANG Nai-Xing ZHANG Jun-Ping YANG Yun-Xu WANG Wu-Wei SHENG Rui-Long 《有机化学》2004,24(Z1):31-32
Benzopyran compounds possess diverse pharmacological properties such as β-blockade, anticonvulsant and antimicrobial.[1,2] Our interest has been focused on the synthesis of 1-[6-Fluoro-2S]-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2-ethanediol (6) and 1-[6-fluoro-(2R)-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2-ethanediol (7) which are particularly convenient precursor to (S,R,R,R)-NE (8). 8 containing four asymmetrical carbon atoms was reported to be the most active isomer.[3] Chandrasekhar[4] has reported on the synthesis of 8. The key step to synthesize this compound is to obtain the chiral chromanone 6 and 7. 6 was accomplished in 8 steps by the Clasien rearrangement and a one-pot Sharpless asymmetric epoxidation, but the compound 7 was accomplished in 10 steps. Johannes[5] used Zr-catalytic kinetic resolution of allylic ethers and Mo-catalyzed chromene formation to synthesize 8 in 14 steps. However both of the methods request many synthetic steps and expensive reagents. 相似文献
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A. B. Dobrynin P. I. Gryaznov O. E. Naumova I. A. Litvinov V. A. Alfonsov 《Journal of Structural Chemistry》2008,49(5):917-921
An X-ray study of (3Z)-(±)-4-(2′-hydroxypropyl)amino-and (3Z)-4-(2′-hydroxyethyl)amino-pent-3-en-2-ones is reported. The bond lengths inside the H ring are equalized due to the classical N-H...O hydrogen bond between the carbonyl oxygen and the amino group. In the 4-(2′-hydroxyethyl)amino-pent-3-en-2-one crystal, due to the classical N-H...O bonds, infinite zigzag chains are formed along the 0b axis and arranged into a layered structure due to the weak C-H...O interactions. In (±)-4-(2′-hydroxypropyl)aminopent-3-en-2-one crystal, however, centrosymmetric dimers are formed, which are then linked by weak C-H...O intermolecular interactions to form a layered structure along the a0b plane. 相似文献
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1,4-苯并二氧六环木脂素类天然产物多数具有增加胆碱乙酰化酶和抗肝毒等活性 ,其活性主要源于 1 ,4-苯并二氧六环官能团 [1] . 1 ,4-苯并二氧六环木脂素的消旋全合成已有报道 [2 ] ,但其不对称合成还是空白[3] .我们发展了一条对映选择性合成 1 ,4-苯并二氧六环木脂素的简捷有效的路线 .基于前面的工作 [4 ] ,我们发现 1 ,4-苯并二氧六环醛类衍生物是合成此类天然产物的关键中间体 ,选择 2 - (4-羟基- 3-甲氧基 ) - 3-羟甲基 - 1 ,4-苯并二氧六环 - 6-醛 (1 )作为目标分子 ,其合成路线如下 :Reagents and conditions:( ) Me OH,H2 SO4,9… 相似文献
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YANG Hui QIU Guo-fu FENG Xichun HE Jian-she HU Xian-ming **College of Pharmacy Wuhan University Wuhan P. R. China 《高等学校化学研究》2002,18(4)
IntroductionChloramphenicol,which was isolated fromStreptomyces venezuelae in 1 947[1] ,is used as abroad- spectrum antibiotic possessing activityagainst many Gram- negative and Gram- positivemicroorganisms. (± ) - 2 - Acetamido- 3 - hydroxy- 1 -(4- nitrophenyl) - 1 - propanone[(± ) - 1 ]is one of theintermediates of producing chloramphenicol.Petrow et al.[2 ] reported some transformations of(± ) - 1 in hydrolysis reactions. However,thereaction products were complicated under multiplehydr… 相似文献
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INTRODUCTIONNaftopidil,RS 1 (2 methoxyphenyl) 4 〔3 (1 naphthyloxy) 2 hydroxypropyl〕 piperazine,isanovelantihypertensivedrugcu... 相似文献
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1INTRODUCTIONThephotodimerizationof1,2-bisarylethenederivativesisaconvenientwayforsynthesizingtetraarylsubstitutedcyclobutane.Forthisreason,thephotochemistryofstilbeneandstyrylpyridinederivativeshasbeenextensivelystudied[1,2].UpontheirradiationwithUVlight(?=300~400nm),thesemonomersareconvertedtohead-to-tailphotodimersinpolarsolventwithperfectyields.Inrecentyears,ourgrouphasbeenstudyingthephotodimerizationreactionsofheteroarylethenescontainingbenzoxazolyl[3]andphenyloxazolyl[4]groups.Itw… 相似文献
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The title compound (C13H8N2O3Se-C3H7NO) has been synthesized by a simple synthetic route and by recrystallization from DMF. The molecular structure of this compound was obtained by single-crystal X-ray diffraction. The compound crystallized in the triclinic space group P with a = 7.450(6), b = 8.150(7), c = 13.859(12) , α = 75.014(14), β = 83.072(18), γ = 84.409(14)°, V = 805.0(12)3, Z = 2 and R = 0.0271 for 2575 observed reflections with I > 2σ(I). X-ray analysis reveals that not only intermolecular Se…O and C-H…O interactions, but also π…π stacking interactions exist in the adjacent molecules. The above three kinds of intermolecular interactions extend the complex into an infinite three-dimensional layered network. 相似文献
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Krushna C. Satpathy Ashok K. Panda Rushabha Mishra Aditya P. Chopdar Sarada K. Pradhan 《Transition Metal Chemistry》1991,16(6):628-630
Summary Binuclear metal complexes of the type [M(HMTE)-(H2O)2]2, where HMTE=1-(-hydroxynaphthyl)-2-(3-methyl-5-mercapto-1,2,4-triazolc)2-aza-ethane and M-CuII, CoII, NiII and MnII have been prepared and characterized. An octahedral geometry around the metals is proposed. The complexes have been screened as possible fungicides. 相似文献