Sakineh Asghari,* Zahra Sobhaninia and Zahra Naderi

Department of Chemistry, University of Mazandaran, P. O. BOX 453, Babolsar, Iran
* Corresponding author: E-mail: s.asghari@umz.ac.ir,
Fax: 00981125233702

Abstract
Ethyl 2-oxo-1-cyclopentanecarboxylate undergoes a reaction with dialkyl acetylenedicarboxylate in the presence of triphenyphosphine to produce stable phosphorus ylides in good yields. These ylides undergo intramolecular Wittig reaction in boiling toluene to produce cyclobutene derivatives, which undergo ring-opening reactions to produce dialkyl (Z)- 2-[2-(ethoxycarbonyl)-1-cyclopentenyl]-2-butenedioates.

Keywords: Ethyl 2-oxo-1-cyclopentanecarboxylate, dialkyl acetylenedicarboxylate, triphenylphosphine, intramolecular Wittig reaction.