Nucleophilic substitution reactions of pyranose polytosylates

The 2,3,4-tri-toluenesulfonate ester derivatives of the methyl pyranosides of l-arabinose, d-ribose, d-lyxose, and d-xylose have been prepared, and their substitution reactions with various nucleophiles have been examined. For arabinose, xylose, and ribose, highly regioselective monosubstitutions were observed with benzoate, nitrite, and azide anions. These reactions have led to short and simple routes from d-xylose to l-arabinose derivatives, from l-arabinose to d-xylose derivatives, and from d-ribose to l-lyxose derivatives. The tritosylate derived from methyl alpha-d-lyxopyranoside was unreactive toward nucleophilic substitution reactions, giving instead a dihydropyran product arising from an initial E2 elimination reaction of the 2-tosylate.     

Strongly amenable involutive representations of involutive Banach algebras

Let \(\mathfrak{A }\) be a Banach \(*\) -algebra and let \(\varphi \) be a nonzero self-adjoint character on \(\mathfrak{A }\) . For a   \(*\) -representation \(\pi \) of \(\mathfrak{A }\) on a Hilbert space \(\mathcal{H }\) , we introduce and study strong \(\varphi \) -amenability of \(\pi \) in terms of certain states on the von Neumann algebra of bounded operators on \(\mathcal{H }\) . We then give some characterizations of this notion in terms of certain positive functionals on \(\mathfrak{A }\) . We finally investigate some hereditary properties of strong \(\varphi \) -amenability of Banach algebras.     

Stability of mixed additive-quadratic Jensen type functional equation in non-Archimedean \ell -fuzzy normed spaces

In this papers we prove the generalized Hyers–Ulam–Rassias stability of the following mixed additive-quadratic Jensen functional equation $$\begin{aligned} 2f\left( \frac{x+y}{2}\right) +f\left( \frac{x-y}{2}\right) +f\left( \frac{y-x}{2}\right) =f(x)+f(y) \end{aligned}$$ in non- Archimedean \(\ell \) -fuzzy normed spaces.     

Main-chain side-chain liquid crystal polymer blends for improved physical properties

Previous work has demonstrated that compatible blends of main-chain liquid crystal polymers (LCP) with side-chain LCP's can be prepared. The present work was carried out to extend the scope and application of this finding to liquid crystal polyesters, similar to commercially available LCP's and to demonstrate the effect of the blend composition upon the physical and mechanical properties. A series of melt-processable main-chain polyesters was prepared as well as a series of acrylic polymers and copolymers which possess a side-chain mesogenic unit, similar to that of the main-chain LCP's. While the results of the blending studies of these high molecular weight materials were somewhat ambiguous as to compatibility, there are strong indications that the presence of the side-chain mesogen containing polymers does result in an improvement in the overall mechanical properties of the main-chain LCP.