“Studies on chemical reactivity of some furanone derivatives”

Abstract

Furanones represent a group of heterocyclic systems of special importance. 2(3H)-Furanones are the precursors of a wide variety of heterocyclic systems, and the nucleus of 2(5H)-furanones is the core skeleton of many natural products. In this investigation, two furanone derivatives, one of the 2(3H)-type and the other is its 2(5H)-isomer, are used as starting materials for the construction of some heterocyclic compounds of synthetic and biological importance. The original work of this thesis is presented in two parts:

Part (1): Synthesis and reactions of some 2(3H)- and 2(5H)- furanone derivatives: A comparative study Early, it was reported that condensation of benzoin with ethyl cyanoacetate in the presence of sodium ethoxide led to the formation of 3-cyano-4,5-diphenyl-2(5H)-furanone1. On reinvestigating this reaction, it was possible to isolate this compound together with another product namely 3-cyano-4,5-diphenyl-2(3H)-furanone2. The formation of the latter product is explained on the basis of isomerization of 1 under the basic reaction conditions. Such isomerization is believed to occur via the intermediacy of two carbanion intermediates which are stabilized by both the cyano group at position 3- and the phenyl group at position 5-