Crystal Structure of cis—2—[P,P—Diethoxy） phosphono（m—nitro）benzyloxy]

The crystal structure of the title compound cis-2-[(P, P-Diethoxy)phosphono(m-nitro)benzyloxy]-4-Phenyl-5,5-Dimethyl-1,3,2-Dioxaphosphorinane 2-Sulfide, C22H29NO8P2S, was determined by single crystal X-ray diffraction. It crystallizes in the monoclinic system, space group P21/c, with Mr=529.49, a=9.888(2), b=20.831(4), c=12.797(3) , β=94.42(3)°, V=2628(1) 3, Z=4, Dx=1.338 g/cm3, λ=0.71073, μ=0.2796 mm-1 and F(000)=556. The structure was solved by direct methods. The final R factor is 0.052 and Rw is 0.057 for 1793 unique observed reflections [I≥3σ(I)]. A cis-configuration and a preferred chair conformation for the molecule have been established by X-ray diffraction analysis. The results presented also give a good explanation to the correlation between the configurational assignments and the regularity in the chemical shifts of C4-H and 31P NMR.     

Crystal Structure of 5—（l—Menthyloxy）—3—chloro—4— Pyrrolidinyl—2（5H0—f

The molecular structure of the title compound 5-(l-menthyloxy)-3-chloro-4-pyrrolidinyl-2(5H)-furanone, C18H28ClNO3(Ⅰ), has been determined by X-ray diffraction at 296(1)K. The crystal is monoclinic with space group P21, a=9.457(3), b=10.413(3), c=9.525(2), β=95.19(2)°, V=934(1) 3, Z=2, Mr=341.88, Dx=1.22 g/cm3, μ=2.15 cm-1, F(000)=368. The final R factor is 0.059, and Rw is 0.065 for 1020 observed reflections with I≥3σ(I). The absolute configuration at C(14) of the acetal carbon was proved to be S, taking into account the known configuration of 1R, 2S, 5R-menthyl moiety. There are three rings in the molecule of this compound: the furanone ring, the pyrrolidine ring and the mentholoxy group ring. The franone ring is connected with the pyrrolidine ring and the mentholoxy ring by N atom and μ2-O bridge atom respectively.     

CRYSTAL STRUCTURE OF ERBIUM（Ⅲ）COMPLEX WITH 1，3，5—BENZENETRICARBOXYLIC ACID

<正> The crystal structure of erbium (Ⅲ) complex of 1,3,5-benzenetricar-boxylic acid is reported. The title compound crystallizes in triclinic space group of P1 and cell parameters a = 7. 649(3) ,b= 9. 859(2) ,c= 11. 171 (3) A ;α= 106. 90(2),β= 104. 40(3),γ=107. 20(3)°;Z = 2;V = 716. 5A3.The final R and Rw are 0. 0328 and 0. 0338 respectively. The rare earth ion is nine-coordinated by four oxygen atoms from two carboxylato groups in two 1, 3, 5- benzenetricarboxylato groups and five aqua molecules, forming a distorted monocapped square antiprism. The Er-O distances fall in the range of 2. 327-2. 627A.     

CRYSTAL STRUCTURE OF THE METHYL 4—（N—（1—OXYPROPYL）—N—PHENYLAMINO]—1—[2—（2—THIENYL）ETHYL]—4—PIPERIDINECARBOXYLATE（R31826）HYDROCHLORIDE

<正> C22H28N2O3S.HCl, Mr = 436.9, triclinic,P1;a=8.557(3),b= 10.299(2),c= 13.894(2)A;α= 99.25(1),β=86.64(2),γ= 107.68(2)°;V= 1151.2(3)A3,Z= 2, DC = 1.27g/cm3,R=0.064. The torsion angle C(14)-C(1)-N(2)-0(19) in the title compound is 137.5 being much larger than that (106°) in R30730. The dihedral angle between mean planes of the thiophene ring and piperidine ring is about 83 .     

Stereoselective Synthesis of (Z)-α,β-Unsaturated Ketones via Hydromagnesiation of Alkynylsilanes

α,β-Unsaturated ketones are important synthetic intermediates because of their versatile reactivities and many syn-thetic applications of them have been reported in the literature.[1] However, only a few methods for the synthesis of (Z)-α,β-unsaturated ketones are available. The palladium catalyzed coupling reactions of alkenyl copper reagents with acid chlorides afforded (Z)-α,β-unsaturated ketones.[2] The phase transfer catalyzed hydroacylation of allenes with carbon monoxide, decacarbonyldimanganese and methyl iodide gave (Z)-α,β-unsaturated ketones in a stereospecific process.     

CRYSTAL STRUCTURE OF 2，4—DINITROPHENYL—t—BUTYL NITRONE（DNPBN）

<正> C11H13 N3 O5·t-Bu- N = CHC6H3(NO2)2,Mr = 267. 27, Monoclinic space group C2/c,a= 18. 546(3),b = 5. 729(1),c= 27. 479(5) A,β= 118. 42(1)°/,F = 2567. 6(9)A3,F(000) = 1120,Z=8,Dx=1. 38g/cm3. The structure of DNPBN is akin to that of PBN reported by us except for shorter N - O and C = N bonds.     

Preparation of a Cyclomaltoheptaose （p—cyclodextrin） Cross—linked Chitosan Derivative via Glyoxal or Glutaraldehyde

A cyclomaltohcptaose-β-cyclodextrin (β-CD) crosslinked chitosan derivative via glyoxal or glutaraldehyde was prepared. The structures of β-CD crosslined chitosan with glyoxal or glutaraldehyde were characterized by IR spectra. The surface morphology of the β-CD crosslinked chitosan particles was examined using a scanning electron microscope. The immobilization capacity of β-CD on chitosan was affected on the weight ratio of β-CD/chitosan,the utilization amount of crosslinking agent, the acidity of the reaction system and the temperature.The adsorption for nicotine indicated that the chitosan-β-CD was a good adsorbent.     

SYNTHESIS AND REACTIONS OF BIS（β—ALKOXY—ETHYL CYCLOPENTADIENYL）TITANOUM（ZIRCONIUM）DICHLORIDES

Bis(β-alkoxy-ethyl cyclopentadienyl) titanium (zirconium) dichlorides was newly synthe-sized,and through interfacial polycondensation of bis(β-alkoxy-ethyl cyclopentadienyl) titanium dichlorides with diacids,diphenols,and hydroxy-acids,a series of new titanium polymers were prepared.The polymers obtained are yellow in color,having mol. wts between 10^3-10^6.They possess heat-resistant properties and show better solubilities that Carraher′s series.Thus,TG/DTG determinations showed that while suffering initial loss of wts. at around 260℃-470℃,they remain stable at 600-800℃.Residual wts.are around 50% of the initial at 947.5℃.They are soluble in glacial acetic acid,DMAC,DMF,and DMSO.     

Synthesis and antibacterial activity of C-2(S)-substituted pleuromutilin derivatives

<正>In order to probe the effect of C-2(S)-substituted groups in the antibacterial activity,a series of novel C-2(S)-substituted pleuromutilin analogues of SB-225586 were synthesized and evaluated for their in vitro antibacterial activity.The results of antibacterial activities indicated that C-2(S)-substituted pleuromutilin derivatives retained appreciable antibacterial activity,and the 2-fluorination compounds 6a and 6b are more potent than the corresponding 2-hydroxylation analogues 7a and 7b.     

Crystal Structure of Copper（ Ⅱ）Complex with 3—Hydroxyl—1,5—diazaylo

Crystal structure of copper (II) complex with a new aminocarboxylate ligand, 3-hydroxyl-1, 5-diazacycloheptane-N,N-diacetate, C9H14CuN2O5.H2O, Mr=311.78 is reported. It crystallizes in orthorhombic Pna21 with a=13.340(4), b=8.127(1), c=10.583(4) , V=1147.2(7)3 , Z=4, Dc=1.805g/cm3, μ=19.287cm-1 (MoKα), F(000)=644. The final R and Rw are 0.049 and 0.065 for 888 observed reflections with I≥3σ(I). The result of X-ray structure determination shows that the Cu(Ⅱ) forms a planar complex with two oxygen atoms and two nitrogen atoms of the ligand.     

5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成

以5-雄烯二醇为原料,用微生物转化的方法合成了两个重要的神经甾体5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇。所用菌种总枝毛霉为我们自己筛选,并首次应用于5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成中。     

Synthesis and Characterization of Poly(ε-caprolactone-co-δ-valerolactone) with Pendant Carboxylic Functional Groups

In this paper, aliphatic polyesters functionalized with pendant carboxylic groups were synthesized via several steps. Firstly, substituted cyclic ketone, 2‐(benzyloxycarbonyl methyl)cyclopentanone (BCP) was prepared through the reaction of enamine with benzyl‐2‐bromoacetate, and subsequently converted into the relevant functionalized δ‐valerolactone derivative, 5‐(benzyloxy carbonylmethyl)‐δ‐valerolactone (BVL) by the Baeyer‐Villiger oxidation. Secondly, the ring‐opening polymerization of BVL with ε‐caprolactone was carried out in bulk using stannous octoate as the catalyst to produce poly(ε‐caprolactone‐co‐δ‐valerolactone) bearing the benzyl‐protected carboxyl functional groups [P(CL‐co‐BVL)]. Finally, the benzyl‐protecting groups of P(CL‐co‐BVL) were effectively removed by H₂ using Pd/C as the catalyst to obtain poly(ε‐caprolactone‐co‐δ‐valerolactone) bearing pendant carboxylic acids [P(CL‐co‐CVL)]. The structure and the properties of the polymer have been studied by Nuclear Magnetic Resonance (NMR), Fourier Infrared Spectroscopy (FT‐IR) and Differential Scan Calorimetry (DSC) etc. The NMR and FT‐IR results confirmed the polymer structure, and the ¹³C NMR spectra have clearly interpreted the sequence of ε‐caprolactone and 5‐(benzyloxycarbonylmethyl)‐δ‐valerolactone in the copolymer. When the benzyl‐protecting groups were removed, the aliphatic polyesters bearing carboxylic groups were obtained. Moreover, the hydrophilicity of the polymer was improved. Thus, poly(ε‐caprolactone‐co‐δ‐valerolactone) might have great potential in biomedical fields.     

Fragmentation Mechanism of Trans—α—Aryl—β—enamino Esters

Electron impact-induced fragmentation mechanism of Trans-α-Aryl-β-enamino esters were investigated using mass-analyzed ion kinetic energy (MIKE) spectrometry and high resolution accurate mass data It was found that the main characteristic fragmentations of compounds studied were:an odd electron ion M^ -EtOH was formed by losing a neutral molecule of ethanol;and the skeletal rearrangements took place;and the ring opening reaction happened after losing a carbon monoxide;and the typical McLafferty rearrangement underwent in ester group.The cycliztion reation caused by losing neutral molecule of TsNH2 due to the ortho-effects of substituted group of gromatic ring was also observed.     

环糊精与两种有机物的包合物的不同光解特性

The effectiveness of the solubilization and photodegradation of β-cyclodextrin （β-CD） and hydroxypropyl-β- cyclodextrin （HPCD） on two hydrophobic organic compounds （HOC） of methyl parathion and pentachlorophenol was investigated. The results indicate that the solubilization or photodegradation of two HOC were influenced by complexing with β-CD or HPCD. The solubility of pentachlorophenol （PCP） was increased linearly with β-CD concentration. The solubility of methyl parathion （MPT） was increased with the increase of β-CD concentration initially, however, as the β-CD concentration was enhanced above 3 g/L, the solubility was decreased with increase of β-CD concentration. The solubilities of two HOC were increased linearly with the increase of HPCD concentration. Although the photodegradation of MPT was improved, the photodegradation of PCP was restrained by complexation of HOC with β-CD or HPCD. In a word, the effectiveness of photodegradation or solubilization of HPCD was more significant than that of β-CD. One potential application of such a method was the in situ remediation of hydrophobic organic pollutants in contaminated soil and groundwater or industrial waste streams.     

Synthesis and Liquid Crystalline Properties of 3-Substituted Pentane-2,4-dione, Pyrazole and Isoxazole Derivatives

The γ-substituted β-diketonate 2,4-dioxo-3-pentyl 4-[4-（n-octyloxy）cinnamoyl]oxybenzoate 1 and its pyrazole and isoxazole derivatives （2 and 3 respectively） have been synthesized and characterized by the spectroscopic methods and elemental analysis. The mesogenic properties of these compounds have been studied by polarizing optical microscopy （POM） and differential scanning calorimetry （DSC）. A monotropic nematic mesophase was observed for the β-diketonate 1, in contrast, the pyrazole 2 displays an enantiotropic smectic A and isoxazole 3 exhibits an enantiotropic nematic mesophase. The relationship between the structure and liquid crystalline properties has also been discussed.     

Highly Efficient InBr3 Catalyzed Michael Addition of Indoles to α, β-Unsaturated Esters

A highly efficient synthetic strategy toward Michael addition of indoles to α,β‐unsaturated esters has been developed using Lewis acid InBr₃ as catalyst. The reactions generated 3‐substituted indoles in high yields with excellent regio‐selectivity in the presence of catalytic amount of InBr₃ under mild reaction conditions. The method is simple, efficient and practical.     

From Tri‐O‐Acetyl‐D‐Glucal to (2R,3R,5R)‐2,3‐Diazido‐5‐Hydroxycyclohexanone Oxime

Abstract

Methyl 3‐azido‐2,3‐dideoxy‐α/β‐D‐arabino‐ and ‐α/β‐D‐ribo‐hexopyranosides were transformed into 6‐iodo analogues via p‐tolylsulfonyl compounds. Elimination of hydrogen iodide from 6‐iodo glycosides provided methyl 4‐O‐acetyl‐3‐azido‐2,3,6‐trideoxy‐α‐ and ‐β‐D‐threo‐hex‐5‐eno‐pyranosides or 3‐azido‐4‐O‐p‐tolylsulfonyl‐2,3,6‐trideoxy‐α‐D‐threo‐ and ‐β‐D‐erythro‐hex‐5‐eno‐pyranosides. Ferrier's carbocyclization of 4‐O‐acetyl‐3‐azido‐2,3,6‐trideoxy‐α‐ and ‐β‐D‐threo‐hex‐5‐eno‐pyranosides gave (2S,3R,5R)‐2‐acetoxy‐3‐azido‐5‐hydroxycyclohexanone, which was converted into oxime. The 2‐OAc group in oxime was substituted by azide ion to yield (2R,3R,5R)‐2,3‐diazido‐5‐hydroxycyclohexanone oxime. The configuration and conformation of all products are widely discussed on the basis of the ¹H and ¹³C NMR.     

A New Synthetic Method of Highly Substituted Cyclopentadienes from α,β-Unsaturated Alkynones

Promoted by samarium diiodlde in THF, the α, β-unsaturated alkynones were reduced to afford intermolecular reductive cou-pling products. The multiply substituted cyclopentadienes were prepared conveniently in good yields.     

Cross-aldol Condensation of Cycloalkanones and Aromatic Aldehydes in the Presence of Nanoporous Silica-based Sulfonic Acid (SiO2-Pr-SO3H) under Solvent Free Conditions

The aromatic aldehydes underwent cross aldol condensation with cycloalkanones in the presence of a catalytic amount of nanoporous silica-based sulfonic acid (SiO2-Pr-SO3H) under solvent-free conditions to afford the corresponding α,α’-bis(substituted benzylidene)cycloalkanones in excellent yields with short reaction time without any side reactions. This method is very general, simple and environmentally friendly in contrast with other existing methods. SiO2-Pr-SO3H was proved to be an efficient heterogeneous solid acid catalyst, which could be easily handled and removed from the reaction mixture by simple filtration, and also recovered and reused without loss of reactivity.     

Molecular Dynamics Simulations of a β-Hairpin Fragment of Protein G by Means of Atom-Bond Electronegativity Equalization Method Fused into Molecular Mechanics (ABEEMσπ/MM)

There are some controversial opinions about the origin of folding β‐hairpin stability in aqueous solution. In this study, the structural and dynamic behavior of a 16‐residue β‐hairpin from B1 domain of protein G has been investigated at 280, 300, 350 and 450 K using molecular dynamics (MD) simulations by means of Atom‐Bond Electronegativity Equalization Method Fused into Molecular Mechanics i.e., ABEEMδπ/MM and the explicit ABEEM‐7P water solvent model. In addition, a 300 K simulation of one mutant having the aromatic residues substituted with alanines has been performed. The hydrophobic surface area, hydrophilic surface area and some structural properties have been used to measure the role of the hydrophobic interactions. It is found that the aromatic residues substituted with alanines have shown an evident destabilization of the structure and unfolding started after 1.5 ns. It is also found that the number of the main chain hydrogen bonds have different distributions through three different simulations. All above demonstrate that the hydrophobic interactions and the main chain hydrogen bonds play an important role in the stability of the folding structure of β‐hairpin in solution. Furthermore, through the structural analyses of the β‐hairpin structures from four temperature simulations and the comparison with other MD simulations of β‐hairpin peptides, the new ABEEMδπ force field can reproduce the structural data in good agreement with the experimental data.