P. V. Ramana Reddy

A NEW APPROACH TO THE SYNTHESIS OF ISOMERIC E,Z-AND E,E-BIS(STYRYL)SULFONES AND A STUDY OF THEIR CYCLOPROPANATION

Abstract The E,Z-and E,E-bis(styryl)sulfones (V & X) have been synthesized from 4-methylphenylacetylene (I) and 4-methylstyrene (VI), respectively. The cyclopropanation of V and X with dimethylsulfoxonium methylide by PTC or Corey and Chaykovsky methods gave E,E-1,1′-bis(2-arylcyclopropyl)sulfones (XI) only. The spectral parameters of these compounds have been discussed.

Stereospecific Synthesis of Some New Z- and E-Cyclopropyl Benzyl Sulfones and E,Z- and E,E-Bis(Cyclopropyl)Sulfones by Ptc Method

Abstract The title compounds, Z- and E-(2-aryl-3-arylsulfonylcyclopropyl)benzyl sulfones (V & VI) and E,Z- and E,E-bis(2-aryl-3-arylsulfonylcyclopropyl) sulfones (XI & XII) have been prepared by the reaction of aryl thiocarbenes with Z- and E-styryl benzyl sulfones (I & II) and E,Z- and E,E-bis(styryl) sulfones (VII & VIII) under phase transfer conditions. The geometry of the substrates was found to be retained in the product formation as is evidenced by the PMR spectra, thus, confirming the stereospecificity of the reaction. The bioactive nature of the newly synthesized compounds was assayed.

A Novel and Convenient Synthesis of E,E-bis(Styryl) sulfones and E,E-1,4-Diaryl-1,3-butadienes

Abstract The condensation of 2-phenylethanesulfonylacetic acid (4) with araldehydes (5) in presence of a base gave E-styryl-2-phenylethyl sulfones (6) which on dehydrogenation with DDQ (7) yielded E,E-bis-(styrl)sulfones (8). The 8 on treatment with dichlorotris(triphenyl-phosphine)ruthenium(II) catalyst resulted 1,4-diaryl-1,3-butadienes (9). The configurations of 6, 8 and 9 have been determined based on IR and 1H NMR spectral data.

SYNTHESIS OF SOME NOVEL α,β-ETHYLENIC SULFONES

Abstract Novel unsaturated sulfones E-alkoxy/carbamoyl benzyl styryl sulfones (VI) and E-4(N-benzylcarbamoyl)benzyl styryl sulfones (IX) have been prepared by the Knoevenagel condensation of alkoxy/ carbamoyl benzylsulfonylacetic acid (V) and 4-carboxybenzylsulfonylacetic acid (VIII) with araldehydes. The E-geometry of these compounds has been assigned based on IR and 1H NMR spectral data.

SYNTHESIS AND SPECTRAL STUDIES OF SOME NEW [(ALKOXYCARBONYLVINYL)ARYL- AND BENZYLSULFONYLMETHYL] SULFONES

Abstract Some new 1,1,2-trisubstituted ethylenic sulfones have been prepared by the condensation of aryl- and benzylsulfonylmethylsulfonylacetic acid esters with araldehydes.

Power system model reduction using identification techniques

Abstract Identification techniques are applied to the construction of lower order nonlinear power system equivalents which can be used in stability calculations, and simulation of dynamic and transient conditions of a multimachine power system. Development of an equivalent machine for a group of dissimilar machines operating at a generating station is considered. An efficient algorithm based on the minimum principle to determine the parameters of the equivalent model which is lower in order than the actual system is also presented.

A fast numerical algorithm for transient stability studies of power systems

Abstract A fast numerical solution of a technique for improving the speed of the transient stability solution of power systems is presented in this paper. The system is described by a set of first-order differential equations which consist of both linear and nonlinear parts. The linear set of equations is considered separately and is solved by modal analysis using closed-form solutions. The nonlinear part of the equations is solved by a numerical method. As explicit solutions are available for the linear part of the equations, the solution time is considerably reduced. The proposed technique is employed for computing the transient stability of a sample power system represented in detail. A comparison is made with a conventional solution procedure.