Racematspaltung von (±)-5-äthyl-1-(3,4-dimethoxyphenyl)-6,7-dimethoxy-4-methyl-5H-2,3-benzodiazepin und anomales chiroptisches verhalten der enantiomeren

A process has been developed for resolving 1 , and the anomalous behaviour of the specific rotation of the enantiomers has been studied. It was shown that this is due to the shift in the conformational equilibrium la ? Ib , and not to an epimerization at C-5.     

On the longest run of coincidences

Summary Consider the rectangles of the first k(n) lines of length n in the right-upper integer-lattice, and suppose that its points are labelled randomly by the numbers 1, 2,..., m. The time i is called coincidence if the points (i, 1), (i, 2),..., (i, k(n)) are labelled identically. Asymptotic properties of the longest run of coincidences are discussed under different conditions on k(n).The results are related to a problem of P. Révész: If the points of an n ×n integer-lattice are coloured red and white randomly, what is the largest area of rectangles with red points only.A conjecture is formulated, indicating some peculiar number-theoretic characteristics of some limit-relations in this area.     

Identification of novel chiral aluminium containing oxonium cations in the enantioselective hydrogenation of ethyl pyruvate catalyzed using cinchonidine modified Pt-alumina in acetic acid

Summary The first identification of aluminium containing oxonium cations having chiral atomic groups is described which may play a role in enantioselective hydrogenation of ethyl pyruvate using Pt-alumina catalyst in AcOH. The structure these cations at m/z = 509 and m/z = 567 is: [O{Al(OAc)₂}₂Al(OPy.OLt)]⁺ and [O(AlOAc.OLt)₂Al(OPy)₂]⁺     

Modular Group Algebras with Almost Maximal Lie Nilpotency Indices

Let be a field of positive characteristic and the group algebra of a group . It is known that, if is Lie nilpotent, then its upper (and lower) Lie nilpotency index is at most , where is the order of the commutator subgroup. The authors previously determined those groups for which this index is maximal and here they determine the groups for which it is `almost maximal', that is, it takes the next highest possible value, namely .Presented by V. Dl a b.Dedicated to Professor Vjacheslav Rudko on his 65th birthday.The research was supported by OTKA No. T 037202, No. T 038059 and Italian National Research Project “Group Theory and Application.”     

Gas chromatographic determination of the interconversion energy barrier for dimethyl-2,3-pentadienedioate enantiomers

The enantiomers of dimethyl-2,3-pentadienedioate undergo interconversion during gas chromatographic separation on 2,6-di-O-methyl-3-O-pentyl-beta-, 2,6-di-O-methyl-3-O-pentyl-gamma-, and 2,3-di-O-methyl-6-O-tert butyldimethylsilyl-beta-CD chiral stationary phases. The combination of a deconvolution method with an internal standard was used to determine individual enantiomer peak areas and retention times needed for the calculation of the interconversion rate constants and the energy barrier for dimethyl-2,3-pentadienedioate enantiomers. The kinetic and thermodynamic data obtained for the interconversion data (rate constants, energy barriers, enthalpies, and entropies) were in good agreement with the published data (Trapp, O., Schurig, V., Chirality 2002, 14, 465-470) using permethylated-beta-CD (Chirasil-beta-Dex).     

A polynomial path-following interior point algorithm for general linear complementarity problems

Linear Complementarity Problems (LCPs) belong to the class of \mathbbNP{\mathbb{NP}} -complete problems. Therefore we cannot expect a polynomial time solution method for LCPs without requiring some special property of the coefficient matrix. Our aim is to construct interior point algorithms which, according to the duality theorem in EP (Existentially Polynomial-time) form, in polynomial time either give a solution of the original problem or detects the lack of property P_*([(k)\tilde]){\mathcal{P}_*(\tilde\kappa)} , with arbitrary large, but apriori fixed [(k)\tilde]{\tilde\kappa}). In the latter case, the algorithms give a polynomial size certificate depending on parameter [(k)\tilde]{\tilde{\kappa}} , the initial interior point and the input size of the LCP). We give the general idea of an EP-modification of interior point algorithms and adapt this modification to long-step path-following interior point algorithms.     

Synthesis and application of a fluorous Lawesson's reagent: convenient chromatography-free product purification

[reaction: see text] A fluorous analogue of Lawesson's reagent for thionation of carbonyl compounds has been developed and its use demonstrated on a series of amides, esters, and ketones. The separation of the Lawesson's reagent-derived byproducts can be achieved by a simple fluorous solid-phase extraction.     

Editorial

The credit crisis is a complex societal problem in which many phenomena and actors are involved. If one wants to analyze the causes of this problem, try to stabilize the situation and prevent new fall backs, a multi-disciplinary approach is prescribed. A careful analysis based on the scientific methodology of societal complexity is needed in order to find how the credit crisis happened and how new crises can be prevented. Theories of multiple disciplines must be used by a multi disciplinary team to analyze the situation and to find sustainable options. This process can be accomplished by following the Compram Methodology of DeTombe. The Compram Methodology provides a framework for policy making which includes many methods and tools. The Compram Methodology is specialized to handle complex interdisciplinary world-wide problems and to offer a step-by-step approach of analyzing the problem, finding and implementing sustainable interventions and evaluating the effects. The Compram Methodology offers a bird’s-eye view on the complexity of the problem and gives directions to policy makers to build their decisions on using a multi-disciplinary, multi-actor approach. In this article the credit crisis is discussed in relation with the Compram Methodology. Aspects of the credit crisis are described with an emphasis on the role of the actors. Based on the Compram Methodology directions can be provided for handling the credit crisis and avoiding future similar problems.