新型2-氧代-1,2,4-三唑并[3,2-d][1,5]苯并氧氮杂类稠杂环的合成

将取代色满酮(1)与芳肼反应生成的腙与HNCO发生[3+2]环加成反应,加成产物(2)经氧化得到偕偶氮异氰酸酯(3).化合物3在HBF4的催化下发生环化-重排反应,得到新颖的三环系2-氧代-1,2,4-三唑并[3,2-d][1,5]苯并氧氮杂化合物5a～5g.     

Anions from dihydro substituted ethyl benzoates and quinoline. New hydrogen donors for tin-free radical chemistry

The anions of substituted dihydro ethyl benzoates and quinoline are very good hydrogen donors to radicals in liquid ammonia and DMSO. With 4-substituted dihydro ethyl benzoates the rate of hydrogen transfer decreases and excellent yields of products are obtained by 6-exo ring closure reaction followed by reduction.     

Absolute stereochemistries and total synthesis of (+)-arisugacins A and B, potent, orally bioactive and selective inhibitors of acetylcholinesterase

In the current studies, we used the Kakisawa-Kashman modification of the Mosher NMR method to determine the complete absolute stereochemistry of arisugacins. We also report the convergent total synthesis of (+)-arisugacins A and B by a sequence including (i) ruthenium complex-catalyzed asymmetric reduction of the cyclohexenone derivative; (ii) stereoselective construction of the arisugacin skeleton by a Knoevenagel-type reaction of an α,β-unsaturated aldehyde derivative with production of a 4-hydroxy-2-pyrone derivative as a key reaction; and (iii) stereoselective dihydroxylation to give the diol derivative, followed by deoxygenation. Accordingly, we defined the absolute structures of arisugacins A and B as 4a-(R),6a-(R),12a-(R), and 12b-(S). Finally, we characterized the bioactivities of the synthetic intermediates to understand the structure-activity relationships of the arisugacins.     

Electron impact induced fragmentation of aromatic N-alkoxy-imines I. Ring closure in (M-CH2O)+• ions by intramolecular aromatic substitution

Summary N-Butoxy- and N-propoxy-imines derived fromo-,m-, andp-substituted benzaldehydes (X = F, Cl, Br, I) decompose upon electron impact to the respective aldoximes by loss of C _n H_2n and competitivelyvia 1,5-distonic radical cations by loss of CH₂O to 1,3-distonic ions which eliminate H and/or a halogen atom in the course of homolytic aromatic substitution, giving rise to cyclic (M-CH₂O-H)⁺ or (M-CH₂O-X )⁺ ions.Dedicated with warm regards to Prof. Dr.D. Seebach, Zürich, on the occasion of his 60^th birthday     

New Results on Generalized $c$-Distance Without Continuity in Cone $b$-Metric Spaces over Banach Algebras

In this work, some new fixed point results for generalized Lipschitz mappings on generalized $c$-distance in cone $b$-metric spaces over Banach algebras are obtained, not acquiring the condition that the underlying cone should be normal or the mappings should be continuous. Furthermore, the existence and the uniqueness of the fixed point are proven for such mappings. These results greatly improve and generalize several well-known comparable results in the literature. Moreover, some examples and an application are given to support our new results.     

Some Estimates for $θ$-Type Calderόn–Zygmund Operators and Linear Commutators on Certain Weighted Amalgam Spaces

In this paper, we first introduce some new kinds of weighted amalgam spaces. Then we discuss the strong type and weak type estimates for a class of Calderόn–Zygmund type operators $T_θ$ in these new weighted spaces. Furthermore, the strong type estimate and endpoint estimate of linear commutators $[b, T_θ]$ formed by $b$ and $T_θ$ are established. Also we study related problems about two-weight, weak type inequalities for $T_θ$ and $[b, T_θ]$ in the weighted amalgam spaces and give some results.     

Besov spaces and the multifractal hypothesis

Parisi and Frisch proposed some time ago an explanation for multiscaling of turbulent velocity structure functions in terms of a multifractal hypothesis, i.e., they conjecture that the velocity field has local Hölder exponents in a range [h _min,h _max], with exponents <h occurring on a setS(h) with a fractal dimensionD(h). Heuristic reasoning led them to an expression for the scaling exponentz _p ofpth order as the Legendre transform of the codimensiond-D(h). We show here that a part of the multifractal hypothesis is correct under even weaker assumptions: namely, if the velocity field hasL ^p -mean Hölder indexs, i.e., if it lies in the Besov spaceB _p ^s, , then local Hölder regularity is satisfied. Ifs<d/p, then the hypothesis is true in a generalized sense of Hölder space with negative exponents and we discuss the proper definition of local Hölder classes of negative index. Finally, if a certain box-counting dimension exists, then the Legendre transform of its codimension gives the scaling exponentz _p , and, more generally, the maximal Besov index of order,p, ass _p =z _p /p. Our method of proof is derived from a recent paper of S. Jaffard using compactly-supported, orthonormal wavelet bases and gives an extension of his results. We discuss implications of the theorems for ensemble-average scaling and fluid turbulence.     

Weakly compactly generated Banach spaces and the strong law of large numbers

IfB is a weakly compactly generated Banach space andf: (S,S, ) satisfies the strong law of large numbers, thenf=f ₁+f ₂, wheref ₁ is Bochner -integrable andf ₂ is Pettis -integrable with Pettis norm 0. The decomposition is unique.     

Cramér theorem on symmetric spaces of noncompact type

We prove the Cramér theorem forK-invariant Gaussian measures on irreducible symmetric spacesX=G/K withG semisimple noncompact. To do this we use a kind of Abel transform ofK-invariant measures onX.This research is supported by KBN Grant.