Improved Preparation of 3,17β-Dihydroxyoestra-1,3,5(10),6-tetraene

The title compound is prepared in good yield via the tosylhydrazone of 3,17β-diacetoxyoestra-1,3,5(10)-triene-6-one (Shapiro reaction)     

Synthesis and molecular structure study of 3-methoxy-7α-methyl-6-oxa-9β,14β-estra-1,3,5(10)-trien-17-one in solution

It was established by NMR spectroscopy that the catalytic hydrogenation of 3-methoxy-7α-methyl-6-oxa-14β-estra-1,3,5(10),8-tetraen-17-one leads to the formation of 3-methoxy-7α-methyl-6-oxa-9β,14β-estra-1,3,5(10)-trien-17-one, the structure of which was investigated in solution. The corresponding analog with a free hydroxyl group at the position 3 possesses an antiradical activity at the absence of uterotropic effect.     

Preparation of derivatives of DL-estrone and of 19-norsteroids from 3-methoxy-Δ1,3,5,(10),9(11)-8,14-secoestratetraen-14,17-dione

Summary Starting from S-methoxy-^{1,3,5(10),8,14}-estrapentaen-17-one (II) and its ethylene ketal (III), a combination of hydrogenation, reduction by Birch's and Johnson's methods, and other reactions has given the methyl ethers of DL-estrone and DL-estradiol (I) and (XV), and also DL-19-nortestosterone (XVI), ^4,8-19-norandrostadienedione (VIII) and other steroids.     

Preparation and reaction of bis (perfluoroalkanesulfonyl) methyl halides

Halogenation of the potassium or silver salts of bis(trifluoromethanesulfonyl)methane (CF3SO2)2CH2 and its cyclo analogues 1 with N-fluoro-bis(trifluoromethanesulfonyl)imine [(CF3SO2)2-NF], chlorine or bromine gave good yields of the corresponding α-halo disulfone (CF3SO2)2CHX and cyclo analogues 9, 10. The chemical transformation of these fluorinated α-halo-disulfones are described.     

Improved Syntheses of 3,17β-Diacetoxyestra-1,3,5(10)-Trien-6-One

improved syntheses of 3,17β-Diacetoxyestra-1,3,5(10)-trien-6-one 5 was achieved in 4 steps (respectively in 45% and 56% overall yield) from 19-nortestosterone 1.     

A novel and stereoselective synthesis of 7α-alkynylestra-1,3,5(10)-triene-3,17β-estradiol

Different stereoselective synthetic routes for the preparation of 7α/β-substituted estradiol derivatives, that is, 7α-alkynylestra-1,3,5(10)-triene-3,17β-estradiol (13) and its 17β-acetate derivative (14), are explored. These steroids are key starting materials for Pd-catalyzed Sonogashira cross-coupling reactions to yield potential estrogen receptor (ER) antagonists, ER-based imaging ligands and other multi-functional agents. Initial preparation of 7α-alkynyl nortestosterone derivatives followed by various approaches to aromatize the A-ring, failed. Instead, stereoselective 7α-cyanation before A-ring aromatization, followed by 7α-cyano reduction to the 7α-aldehyde, dibromomethylenation and dehydrobromination of the aldehyde, gave the desired 7α-alkynyl derivatives 13 and 14 in good yield.     

Characterization and modelling of a gasoline containing 1,1-dimethylethyl methyl ether (MTBE), diisopropyl ether (DIPE) or 1,1-dimethylpropyl methyl ether (TAME) as fuel oxygenate based on new isothermal binary vapour–liquid data

Experimental isothermal P–x data at T=313.15 K for seven binary systems (1,1-dimethylethyl methyl ether (MTBE)+2,2,4-trimethylpentane); (1,1-dimethylethyl methyl ether (MTBE)+toluene); (toluene+2,2,4-trimethylpentane); (toluene+1-hexene); (toluene+cyclohexane); (2,2,4-trimethylpentane+1-hexene) and (2,2,4-trimethylpentane+cyclohexane) are reported. Data reduction by Barker’s method provides correlations for G^E using the Margules equation, Wilson, NRTL and UNIQUAC models, which have been applied successfully. We have compared the behaviour in the vapour–liquid equilibrium of the aromatic compounds benzene and toluene and the paraffins heptane and 2,2,4-trimethylpentane. And finally we have modelled a gasoline of five components using the Wilson model, and we have compared the influence of three different ethers used as oxygenated additives in gasolines.     

Syntheses of(C_8H_8)Ln(C_9H_7)·(THF)_2(Ln=Pr,Nd)and crystal structure of(C_8H_8)Pr(C_9H_7)·(THF)_2

This paper reports two lanthanide complexes of formula (C_9H_7)Ln(C_8H_8)·(THF)_2 whereLn is Pr or Nd,C_9H_7 is indenyl,and C_8H_8 is cyclooctatetraene (COT).The complexes were preparedby the reaction of LnCl_3 with K(C_9H_7) and K_2(C_8H_8) in THF.(C_9H_7)Pr(C_8H_8)·(THF)_2 crystallizes inTHF at - 15℃ in the monoclinic space group P2_1:with unit cell dimensions a=8.446(0),b=10.083(2),c=13.407(3),β=105.48(1)°,V=1100.43(35)~3,Dc=1.52g/cm~3 and Z=2.The final R valueis 0.033,R_w value is 0.030,respectively.In (C_9H_7)Pr(C_8H_8)·(THF)_2 a five-membered ring centroid ofC_9H_7,the C_8H_8 ring centroid and the two oxygen atoms from the two THF molecules form a distortedtetrahedral geometry around the metal.     

Preparation and characterization of tetrakis (β-ketophosphonato) thorium(IV) complexes

Tetrakis (β-ketosphonato) thorium(IV) complexes have been prepared using a liquid—liquid extraction method. They have been well characterized by i.r., Raman, ¹H, ¹³C and ³¹P NMR spectroscopies. β-ketophosphonates act as anionic chelating ligands and are coordinated by the PO and CO oxygen atoms. An asymmetric repartition of the negative charge on the chelate ring is observed. A stabilities order of the studied β-ketophosphonato-thorium complexes has been established.     

Isomerization of 14-hydroxy-17-ketosteroids: New examples of two-centered inversion of the C/D ring fusion and X-ray diffraction structural analysis of d,ℓ-3-methoxy-14β-hydroxy-8β, 9α-estra-1,3,5(10)-trien-17-one

d,-3-Methoxy-14-hydroxy-8,9-estra-1,3,5(10)-trien-17-one (I) undergoes two-centered isomerization in alkaline medium to d,-3-methoxy-14-hydroxy-8,9-estra-1, 3,5(10)-trien-17-one (II) in 70% yield. Under analogous conditions, natural isomer (II) is converted into synthetic isomer (I) in 20% yield. The crystalline and molecular structure of isomer (II) was established.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2878–2883, December, 1991.     

BF3·Et2O-catalyzed rearrangement of 7-epimeric 3β,7-diacetoxy-9β,11β-epoxy-5α-lanostanes. Formation of novel 19(10→9β)abeo- and 19(10→9β), 30(14→8α)bis-abeo-lanostane derivatives

The boron trifluoride etherate catalyzed reaction of 7-epimeric 3β,7-diacetoxy-9β,11β-epoxy-5α-lanostanes 1 and 2 in acetic anhydride resulted in the formation of a series of skeletally rearranged products, mainly 19(10→9β)abeo-lanostanes. 19(10→9β),30(14→8α)Bis-abeo-lanostane derivative 5 possessing a novel type of the triterpene skeleton was formed as the major product in the reaction of 7α-epimer 2. The direction and extent of rearrangements of 9β,11β-epoxides 1 and 2 depends on the configuration of the 7-acetoxy group. The structures of the new compounds were determined on the basis of spectroscopic methods, mainly ¹H and ¹³C NMR. The structure of compound 5 was confirmed by single-crystal X-ray diffraction.     

Preparation of hierarchical β-Ni(OH)2 nanostructures and adsorption characterization of methyl orange dye

The β-Ni(OH)₂ nanostructures have been prepared by hydrothermal with ammonia as alkali source. The morphology of β-Ni(OH)₂ evolves from hexagon sheets to flower-like hierarchical structure built up from the nanosheets as increasing the amount of ammonia. Hierarchical β-Ni(OH)₂ nanostructures have strong adsorption effect on methyl orange dyes. The adsorption mechanism of β-Ni(OH)₂ has been investigated, which could be expressed by pseudo-second order kinetic model with best match.     

Molecular dynamics simulations of the hydration of poly(vinyl methyl ether):Hydrogen bonds and quasi-hydrogen bonds

Atomistic detailed hydration structures of poly(vinyl methyl ether)(PVME) have been investigated by molecular dynamics simulations under 300 K at various concentrations. Both radial distribution functions and the distance distributions between donors and acceptors in hydrogen bonds show that the hydrogen bonds between the polymer and water are shorter by 0.005 nm than those between water molecules. The Quasi-hydrogen bonds take only 7.2% of the van der Waals interaction pairs. It was found the hydrogen bonds are not evenly distributed along the polymer chain,and there still exists a significant amount(10%) of ether oxygen atoms that are not hydrogen bonded to water at a concentration as low as 3.3%. This shows that in polymer solutions close contacts occur not only between polymer chains but also between chain segments within the polymer,which leads to inefficient contacts between ether oxygen atoms and water molecules. Variation of the quasi-hydrogen bonds with the concentration is similar to that of hydrogen bonds,but the ratio of the repeat units forming quasi-hydrogen bonds to those forming hydrogen bonds approaches 0.2. A transition was found in the demixing enthalpy at around 30% measured by dynamic testing differential scanning calorimetry(DTDSC) for aqueous solutions of a mono-dispersed low molecular weight PVME,which can be related to the transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ～27%. The transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ～27% can be used to explain the demixing enthalpy transition at 30% at a molecular scale. In addition,at the concentration of 86%,each ether oxygen atom bonded with water is assigned 1.56 water molecules on average,and 'free' water molecules emerge at the concentration of around 54%.     

Synthesis and crystal structure of complexes of manganese(II), cobalt(II), and nickel(II) isothiocyanates with ?-caprolactam

The possibility of ?-caprolactam (CPL) to coordinate to manganese(II), cobalt(II), and nickel(II) rhodanides has been investigated. New complexes trans-[M(CPL)₄(NCS)₂], where M = Mn (I), Co (II), and Ni (III), have been synthesized. The complexes have been studied by chemical analysis and IR spectroscopy. According to X-ray diffraction, complexes are isostructural to each other and crystallize in monoclinic space group P2₁/c, Z = 2. For I: a = 6.9457(2) ?, b = 17.7751(6) 0A, c = 12.8999(4) 0A, ?? = 104.2670(10)°, V = 1543.51(8) ?³, ??_calc = 1.342 g/cm³, R ₁ = 0.0426. For II: a = 6.8925(2) ?, b = 17.8189(8) ?, c = 12.7278(6) ?, ?? = 104.421(2)°, V = 1513.93(11) ?³, ??_calc = 1.377 g/cm³, R ₁ = 0.0280. For III: a = 6.7804(2) ?, b = 18.4631(4) ?, c = 12.4841(3) ?, ?? = 105.2950(10)°, V = 1507.49(7) ?³, ??_calc = 1.382 g/cm³, R ₁ = 0.0273. Structures I?CIII are molecular; the metal atom in each of them coordinates four CPL molecules and two NCS groups via oxygen and nitrogen atoms, respectively.     

光学活性17β-叔-丁氧基-3-甲氧基-7a(或7β),18-二甲基-1,3,5(10)-雌甾三烯的合成

合成7α,18-二甲基-19-去甲基-甾体物的关键中间体10a是通过从3a与4的缩合物5经氢化、环合、再氢化而得到.同样地可获得7β,18-二甲基雌甾二醇衍生物10b即:6→7b→9b→10b.     

Preparation and structure of poly(4,4′-oxydiphenylene)pyromellitimide asymmetric ultrafiltration membranes

A process was developed for preparing asymmetric ultrafiltration poly(4,4′-oxydiphenylene)pyromel litimide membranes, involving wet forming of the membranes from the prepolymer, followed by catalytic solidphase thermal transformation of the prepolymer into the polyimide. The influence exerted on the structure and characteristics of the membranes by the compositions of the forming solution and precipitation bath, and also by thermal imidization conditions was examined. The optimal conditions were determined for preparing asymmetric ultrafiltration poly(4,4′-oxydiphenylene)pyromellitimide membranes exhibiting the water permeability coefficient of (10−500) × 10⁻⁶ m³ m⁻² s⁻¹ atm⁻¹ and molecular weight cut-off in the range (5−100) × 10³ g mol⁻¹.     

Über die Identifizierung der Lokalanaesthetica (L-A) Butacain (1), Butethamin (2), Chloroprocain (3), Dyclonin (4), Äthylaminobenzoat (5), Lidocain (6), Meprylcain (7), Metalbutethamin (8), Metabutoxycain (9), Naepain (10), Parethoxycain (11), Piperocain (12), Procain (13), Proparacain (14), Propoxycain (15) und Tetracain (16)

Analytical and Bioanalytical Chemistry -     

13β-乙基-3-甲氧基-甾-1,3,5(10),9(11)-四烯-17β-醇的间氯过氧苯甲酸氧化反应

11—酮基雌甾化合物是合成具有强效抗生育活性11—烃基甾体化合物的关键中间体。文献报道雌甾—1,3,5(10),9(11)—四烯类化