Synthesis of Anhydronectriachrysone,an Extensively Conjugated γ-Pyrone

The synthesis of anhydronectriachrysone (2) through the DIBAH reduction of toralactone (3), followed by dehydration of the corresponding lactol (4) is reported (38% yield).     

Synthesis and Characterization of New γ-Substituted Pentamethine Cyanine Dyes

Three novel pentamethine cyanine dyes with 3,5-dimethylpyridinium-1-yl and 4-benzylpyridinium-1-yl substituents in γ position of the methine chain were synthesized via a three-step procedure. The visible spectral behavior of these pentamethine cyanine dyes was examined in DMSO. Elemental analysis, IR, ¹H-NMR, ¹³C-NMR, and Mass spectral data confirmed the molecular structure of the newly synthesized compounds.     

Synthesis and Characterization of AmmoniumMolybdostibophosphate

以简单酸铵盐为原料，采用不同的磷钼锑比，在控制反应温度７０～８０℃、溶液酸度２．５～３．０Ｎ的条件下，进行分步反应的方法，首次合成了以锑原子取代的钼锑磷杂多酸铵。通过元素分析，确定了它们的组成；用ｐＨ滴定曲线、电子吸收光谱和Ｘ射线等方法研究了它们的性质。     

Synthesis of New N-Sulfonyl Monocyclic β-Lactams and the Investigation of Their Antibacterial Activities

New monocyclic β-lactams 4–6 were synthesized by a ketene-imine [2+2] cycloaddition reaction. The prepared monocyclic β-lactams 4–6 were cleaved by ceric ammonium nitrate (CAN) to give NH-β-lactams 7–9. The NH-β-lactams were converted to N-sulfonyl β-lactams 10–21 by treatment with four different sulfonyl chlorides in the presence of Et₃N and 4-N,N-dimethylaminopyridine (DMAP). Some of these monocyclic β-lactams were active against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Studies on the Microbial Synthesis and Characterization of Polyhydroxyalkanoates Containing 4-Hydroxyvalerate Using γ-Valerolactone

In this study, the ability of Cupriavidus sp. USMAA2-4 to synthesize polyhydroxyalkanoates (PHA) containing 4-hydroxyvalerate monomer (4HV) was studied through one-stage cultivation using γ-valerolactone as the carbon precursor. The presence of 4HV monomer unit in the polymer was detected through gas chromatography analysis, proving the capability of this wild strain bacterium to produce poly(3-hydrxybutyrate-co-3-hydroxyvalerate-co-4-hydroxyvalerate) [P(3HB-co-3HV-co-4HV)] terpolymer. Existence of a 4HV monomer unit in the PHA produced was further confirmed through ¹³C and ¹H NMR analysis. P(3HB-co-88 % 3HV-co-1 % 4HV) terpolymer with the highest PHA content of 63 wt% was obtained through combination of 0.14 wt% C of γ-valerolactone with 0.42 wt% C of oleic acid. Various compositions of P(3HB-co-3HV-co-4HV) terpolymer with 3HV and 4HV compositions ranging from 11 to 94 mol% and from 1 to 4 mol%, respectively, were acquired by manipulating γ-valerolactone and oleic acid concentrations. The molecular weight and the thermal and mechanical properties of four different compositions of terpolymers—P(3HB-co-91 % 3HV-co-1 % 4HV), P(3HB-co-55 % 3HV-co-2 % 4HV), P(3HB-co-27 % 3HV-co-2 % 4HV), and P(3HB-co-9 % 3HV-co-1 % 4HV)—were characterized. Among these terpolymers, P(3HB-co-27 % 3HV-co-2 % 4HV) terpolymer with a molecular weight of 5.7 (10⁵ Da) exhibited the highest elongation to break (264 %). The monomer unit compositional distributions of these terpolymers were investigated through acetone–water fractionation analysis. The results suggested that these produced terpolymers had broad 3HV compositional distribution and narrow 4HV compositional distribution.     

N-Aryl Modification in γ-Lactam: Design and Synthesis of Novel Monocyclic γ-Lactam Derivatives as Inhibitor for Bacterial Propagation

In search of novel γ-lactam antibacterial agents as non-β-lactam mimics of some γ-lactam antibiotics, N-aryl modification in the γ-lactam ring has been made to synthesize compounds 4–8 in two to six steps. Compound 4 was synthesized using the intermolecular Michael addition of diethyl N-(6-coumarinyl)-2-aminomalonate and 3-aryl/(2-heteroaryl)acryloyl chloride followed by intramolecular amidification. Hydrolysis and stereoselective decarboxylation of 4 resulted in the formation of trans- γ-lactam carboxylic acids (5), which on side chain homologation followed by saponification of the intermediate γ-lactam monoester (7) afforded γ-lactam carboxylic derivatives 8. Moderate to good bacterial growth inhibition was observed for some of the synthesized compounds against E. coli and S. aureus.     

Synthesis and Characterization of ZnO Nanowires

Zinc oxide is a wide bandgap (3.37 eV) semiconductor with a hexagonal wurtzite crystal structure. ZnO prepared in nanowire form may be used as a nanosized ultraviolet light-emitting source. In this study, ZnO nanowires were prepared by vapor-phase transport of Zn vapor onto gold-coated silicon substrates in a tube furnace heated to 900 ?C. Gold serves as a catalyst to capture Zn vapor during nanowire growth. Size control of ZnO nanowires has been achieved by varying the gold film thickness…     

Synthesis and Characterization of Ion-exchange Copolyimide

A new diamine, disodium 4, 4‘-di(4-aminophenoxy)-3, 3‘-disulfonate-1, 1‘-diphenylketone, was prepared from the nucleophilic substitution of disodium 4, 4‘-difluoro-3, Y-disulfonate-1, l‘-diphenylketone and p-aminophenol. Polymerization of this diamine and 4,4‘-diamino-1, 1‘-diphenyl ether with 3, 3‘, 4, 4‘-tetracarboxyl dianhydride-1, 1‘- diphenyl ketone gave ion-exchange copolyimide. The new diamine and its polyimide were characterized with ^1H-NMR and FT-IR.     

Sustainable Synthesis of the Naturally Hypolipidemic Agent α-Asarone

A short and practical preparation of α-asarone was developed using the inexpensive methylisoeugenol as a starting material. The utilization of a sequence of tribromination, debromination, and copper-mediated aromatic substitution enabled the stereoselective formation of only the E-isomer of α-asarone in good yield.     

Synthesis and Structure of 2,3-Tetra-Methylene-5,6-Trimethylene-4-Pyrone

Weattemptedtosynthesizecompound(I)bythtereactionofadipylchloridewithcyclohexanonepiperidineenamineI'1-However,weobtainedinsteadthederivativeofa4-pyrone(U)whichmaybepossiblyapotentialmedicinef[2.3]EXPERIMENTALToastirredaolutioncontainingcyclohexanonepiperidineenamine,triethylamine'andchloroform,adipy1chloridedissolvedinchloroformwasaddeddropwiseatroomtemperature.Themixturewasrefluxedfor1h,cooledandhydrolyzedwithhydrochloricacidforanother1h.Theorganiclayerwasseparated,wasbedwithwater,drie…     

Synthesis and Characterization of the Tetrazole Analogues of α-Amino Acids

Tetrazoles have found wide applications in coordination chemistry, medicinal chemistry and material science. Especially, when the tetrazole moiety is served as a surrogate for terminal carboxylic acid residues, the peptides have been presented some pharma…     

Synthesis and Characterization of the Host-Guest NanocompositeMaterial Zeolite Y-Iron Bipyridine

Zeoliteshavethedefinedcrystallinestructureswiththechannelsorcagesofnanoscaledimensions.Thesechannelsorcagesofzeolitescanoffertheloadingsitestoselfassembleandstabilizetheentrappedguestwithinthezeolitesthatcanbeusedforusefulmatrixestoproducenanoguestsmaterialsl.Becausethiskindofmaterialsshowedsomespecialproperty=,ithasarousedmuchinterest3.Anewfieldofinvestigationfortheentrappedmetalcomplexeshasbeendevelopedinelectro-assistedcatalysisoforganicreaction'.Atpresent,therearethreeapproachestotheprepar…     

Synthesis and Characterization of Heteropolytungstosilicate Complexes with the Lanthanide Elements

Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial oxygen in Ln(SiW9)2 was coordinated with Ln3- , where Ln-3 was in the inner side of the heteropoly anions, while the fundamental structure of SiW9 had little change. The result was supported by ion exchange experiment.     

First Synthesis of a Series of New Natural Glucosides

Alkyl glucoside 1 and aryl glycosides 2-4 were highly stereospecifically synthesized over 4-6 steps from commercially available starting materials. The coupling reaction of the acetobromo-α-D-glucose with the unprotective dihydroxy aglycon in the presence of silver oxide, or with aromatic aglycon in the presence of sodium hydroxide produced the key intermediate. Only β-configuration glycosides were formed in this procedure. The synthesis of all these glycosides was reported for the first time.     

Synthesis and Characterization of Novel N-Ferrocenesulfonyl Benzimidazole

A new series of ferrocenesulfonyl benzimidazle has been synthesized and characterized by 1H NMR, FT-IR and elemental analysis. They are expected to have special bio-activity.     

Synthesis and Characterization of Copolymercore-Silvershell Composite Microspheres

Composite microspheres composed of monodispersed poly（St-co-MAA） latices with diameter about 260 nm as core and Ag nanocrystals as shell were prepared by an in situ reduction method. The shell thickness could be controlled in the range of 15--45 nm by this coating process. The structure and the composition of the core-shell microspheres were characterized by transmission electron microscopy （TEM）, X-ray diffractometry （XRD）, X-ray photoelectron spectroscopy （XPS）, and thermogravimetric analysis （TG）. The formation of the composite microspheres is explained by the nucleation of silver on the surface of the latices followed by growth of the silver shell.     

Synthesis and Characterization of ChiralLiquid Crystal CMPPCDP

ＳｙｎｔｈｅｓｉｓａｎｄＣｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆＣｈｉｒａｌＬｉｑｕｉｄＣｒｙｓｔａｌＣＭＰＰＣＤＰＴＩＡＮＹａｎ－ｑｉｎｇ，ＺＨＡＯＹｉｎｇ－ｙｉｎｇ，ＳＵＦｅｎｇ－ｙｕａｎｄＴＡＮＧＸｉｎ－ｙｉ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔ...     

Synthesis and Characterization of Linear Water-soluble γ-Cyclodextrin based Polymers as Drug Carrier Systems

A series of new linear water-soluble homo and copolymers of γ-cyclodextrin are reported. These water-soluble polymers were synthesized from γ-cyclodextrin (γ-CD) and triazine through a single pot condensation polymerization procedure and the synthetic parameters optimized. Lactose and maltose based γ-cyclodextrin copolymers were also prepared. The physicochemical properties of these synthesized polymers were characterized by FT-IR spectroscopy, XRD analysis, thermogravimetry analysis (TGA) and aqueous solubility determination. The formation of a 1:1 efavirenz (an anti HIV drug)/γ-CD polymer inclusion complex was confirmed from FT-IR and UV–VIS spectroscopy and phase solubility studies. The release performance of efavirenz was investigated through phase solubility and dissolution studies. It was found that these copolymers showed improved drug dissolution abilities.     

Synthesis of γ-benzyltert-butoxycarbonyl-L-alanyl-D-glutamate and its derivatives

A convenient method of obtaining Boc-L-Ala-D-iGln-OBzl and its amide analogs by condensing the N-hydroxysuccinimidyl ester of Boc-L-Ala with the -benzyl ester ofD-Glu in the presence of NaHCO₃, followed by amidation of the resulting Boc-L-Ala-D-Glu--OBzl, is proposed. The use of l-adamantylamine and octadecylamine as amino components has enabled the corresponding -adamantylamide and octadecylamide of the dipeptide to be obtained.Simferopol' State University, 4 Yaltinskaya ul., Simferopol', Crimea, Ukraine 333036. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 101–103, January–February, 1998.     

Synthesis and certain transformations of γ-nitrosoalcohols

The -nitrosoalcohols (II), (XII), and (IX), respectively, have been synthesized by acid-catalyzed hydrolysis of 2-alkoxyisoxazolidines (I), (Xa, b), (Xla, b), and 3-(dimethoxyamino)-3-trifluoromethylbutanol-1 (VIII). The nitrosoalcohol (II) readily rearranges into the oxime (III), and (XII) is converted into the diol (XIII) by oxidation with atmospheric O₂ and denitrosation. For (IX) and (XII) ring-chain tautomerism with formation of 2-hydroxyisoxazolidines could not be detected by PMR spectroscopy.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1563–1568, July, 1991.