Global Interval Methods for Local Nonsmooth Optimization

An interval method for determining local solutions of nonsmooth unconstrained optimization problems is discussed. The objective function is assumed to be locally Lipschitz and to have appropriate interval inclusions. The method consists of two parts, a local search and a global continuation and termination. The local search consists of a globally convergent descent algorithm showing similarities to -bundle methods. While -bundle methods use polytopes as inner approximations of the -subdifferentials, which are the main tools of almost all bundle concepts, our method uses axes parallel boxes as outer approximations of the -subdifferentials. The boxes are determined almost automatically with inclusion techniques of interval arithmetic. The dimension of the boxes is equal to the dimension of the problem and remains constant during the whole computation. The application of boxes does not suffer from the necessity to invest methodical and computational efforts to adapt the polytopes to the latest state of the computation as well as to simplify them when the number of vertices becomes too large, as is the case with the polytopes. The second part of the method applies interval techniques of global optimization to the approximative local solution obtained from the search of the first part in order to determine guaranteed error bounds or to improve the solution if necessary. We present prototype algorithms for both parts of the method as well as a complete convergence theory for them and demonstrate how outer approximations can be obtained.     

Direct preparation of polyfunctional amino-substituted arylmagnesium reagents via an iodine-magnesium exchange reaction

The successive addition of PhMgCl and i-PrMgCl to functionalised iodoanilines allows their conversion to the corresponding amino-functionalised Grignard reagents, which react smoothly with a range of electrophiles in high yield.     

Supramolecular Inclusion Hosts Based on Amino Acid Compound Sources: Design, Synthesis and Crystalline Inclusion Behaviour. X-Ray Crystal Structures of Two Inefficient Host Compounds

A new design of crystalline hosts derived from amino acids, characterised by an amino- ethanol functional unit or its carbonamide structural derivative and appended aromatic residues including secondary substituents, is reported. The syntheses of corresponding compounds (1–15) are described. Crystalline inclusion formation is shown and discussed with reference to structural parameters of the host molecules. X-Ray crystal structures of compounds 3 and 11 have been determined in order to suggest reasons for their failure to show inclusion ability.     

d‐Secoestrone derivatives. V

The two title 16,17‐secoestrone derivatives, 3‐methoxy‐17‐oxo‐17‐phenyl‐16,17‐secoestra‐1,3,5(10)‐triene‐16‐nitrile, C₂₅H₂₇NO₂, (I) (17‐oxo substituent), and 17‐hydroxy‐3‐methoxy‐17‐phenyl‐16,17‐secoestra‐1,3,5(10)‐triene‐16‐nitrile, C₂₅H₂₉NO₂, (II) (17‐hydroxy substituent), have quite different conformations in the solid state. These conformational differences can be minimized by molecular mechanics calculations. Thus, the remarkable difference in the biological activity of the two compounds, e.g. the strong oestrogenic characteristics of (I) and the moderate antioestrogenic action of (II), must be caused by the difference in substitution at C17. In (II), the mol­ecules are linked by O—H?N hydrogen bonds, forming spirals along the b direction.     

Synthesis of Anticancer Compounds,I, “Dual Function” Antitumor Agents Based on Bioreduction and <Emphasis Type="Italic">DNA</Emphasis>-Alkylation

Summary. We report the synthesis of novel anticancer compounds based on bioreductive and DNA-alkylating properties. The strategy was to combine a benzoquinone annelated pyrrole with bioreductive properties with a set of DNA-alkylating functionalities, thus resulting in bifunctional anticancer compounds. The biological activity of all compounds was evaluated against a number of cancer cell lines. One of the compounds should be emphasized.     

Preparation of delta-Chloro-alpha-allenyl Ketones by Acylation of 3-Buten-1-ynes

AlCl(3)-mediated acylation of 3-buten-1-yne derivatives with acyl chlorides yields a mixture of 5-chloro-2,3-pentadienones and 3-chloro-2,4-pentadienones. The proportion of allenyl ketones vs conjugated dienic ketones depends on the substitution pattern of the starting enyne. Acylation of 5-acetoxy-3-buten-1-ynes leads to the corresponding allenyl ketones (6-acetoxy-5-chloro-2,3-pentadienones).     

The determination of trace elements in crude oil and its heavy fractions by atomic spectrometry

A literature review on the determination of trace elements in crude oil and heavy molecular mass fractions (saturates, aromatics, resins and asphaltenes) by ICP-MS, ICP OES and AAS is presented. Metal occurrences, forms and distributions are examined as well as their implications in terms of reservoir geochemistry, oil refining and environment. The particular analytical challenges for the determination of metals in these complex matrices by spectrochemical techniques are discussed. Sample preparation based on ashing, microwave-assisted digestion and combustion decomposition procedures is noted as robust and long used. However, the introduction of non-aqueous solvents and micro-emulsions into inductively coupled plasmas is cited as a new trend for achieving rapid and accurate analysis. Separation procedures for operationally defined fractions in crude oil are more systematically applied for the observation of metal distributions and their implications. Chemical speciation is of growing interest, achieved by the coupling of high efficiency separation techniques (e.g., HPLC and GC) to ICP-MS instrumentation, which allows the simultaneous determination of multiple organometallic species of geochemical and environmental importance.     

Formation of large PEE domains in PEE212-PEO112 diblock copolymer monolayers: shift of the PEO-desorption transition

PEE212-PEO112 diblock copolymer monolayers are studied at the air/water interface. At large molecular areas, with X-ray reflectivity, PEE domains are observed, which are partly immersed into the water. The domain thickness increases on compression (28 to 40 A). With off-specular X-ray reflectivity, an average domain radius of 750 A is found, but there are also smaller domains. Due to these space constraints, most PEO blocks form a brush beneath the PEE domains. Only a few PEO blocks form a corona surrounding the domains and adsorb flatly onto the air/water interface. The PEO desorption transition is observed at the typical pressure of 9 mN/m, when the flatly adsorbed PEO is compressed at a domain fraction of 95%. It occurs at 6 A2/EO monomer, about half the value found for lipopolymers or diblock copolymers with NPEE approximately NPEO or NPEE < NPEO. Apparently, the thickness of the PEE domains is determined by the forces from the two interfaces, not by the PEO block, for which flat adsorption beneath the domain would be more favorable instead of formation of a PEO brush.     

Aristoserratenine and tasmanine: structures and absolute configurations

The structure of the Aristorelia alkaloid aristoserratenine ($\text{1}$) has been determined by spectroscopic means, and confirmed by rearrangement to aristoteline ($\text{2}$). The structure of tasmanine ($\text{3}$) has been confirmed similarly, and the configuration at the spiro carbon of each base has been determined by nOe experiments.