Simple and one-pot synthesis of tri and tetracyclic frameworks containing [1,8]naphthyridin-2-one moiety from the Baylis-Hillman adducts

A facile synthesis of tri and tetracyclic frameworks containing [1,8]naphthyridin-2-one skeleton from the Baylis-Hillman alcohols via the Johnson-Claisen rearrangement, followed by the treatment with Fe/AcOH in simple one-pot multi-step process is described.     

Titrimetric determination of gold by precipitation with hydroquinone

A rapid method for the volumetric determination of gold is described. Gold(III) is reduced to metal with excess of hydroquinone at room temperature and the excess is titrated with ceric sulphate. The effect of chloride ion on the reducibility of gold(III) to the metal is discussed. This method can be successfully employed for the determination of gold in presence of certain base and noble metals. The method was successfully adopted for the determination of gold in a commercial sample.     

Influence of temperature on the photometric determination of silicon by the molybdenum blue methods

Some systematic studies have been carried out on the influence of temperature on the photometric determination of silicon by the molybdenum blue procedure. It has been shown that temperature exerts a distinct influence on the colour intensities involved in the different procedures and the extent of this influence depends largely on the nature of the acid medium and the reducing agent employed. Ascorbic acid has been successfully employed to overcome the influence of temperature. Our thanks are due to the management of the Tata Iron and Steel Company for permitting the publication of this paper.     

Preparation of 2,9-dioxabicyclo[3.3.1]nonanes. A model for tirandamycin

An efficient synthesis of a 2,9-dioxabicyclo[3.3.1]nonane system, similar to that of tirandamycin, is accomplished from 2,3-dimethylfuran.     

On the symmetry of L1 algebras of locally compact motion groups,and the Wiener Tauberian theorem

Let G be a locally compact motion group, i.e., it is a semidirect product of a compact subgroup with a closed abelian normal subgroup, the action of the compact subgroup on the other one being by conjugation. The main result of this paper is that the group algebra of such a group is symmetric. This result is then used to prove that a generalization of the Wiener-Tauberian theorem holds for such groups. Precisely, it is shown that every proper closed two-sided ideal in L₁(G) is annihilated by an irreducible unitary representation of G, lifted to L₁(G).     

Recursion operator for coupled KdV equation

The recursion operator for the infinitesimal transformations about solutions of the coupled KdV is obtained as a 2 × 2 matrix.