Effect of pressure on the (2 + 2) cycloaddition of cyclopropanone diethyl acetal to tetracyanoethylene

✍ Scribed by Petrus G. Wiering; Herbert Steinberg

• Book ID: 104588441
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 271 KB
• Volume: 101
• Category: Article
• ISSN: 0165-0513
• DOI: 10.1002/recl.19821010707

✦ Synopsis

Abstract

The pressure dependence of the (2 + 2) cycloaddition of cyclopropanone diethyl acetal to tetracyanoethylene in methylene chloride and acetonitrile has been studied. The reaction is about ten times faster in the less polar methylene chloride in the pressure range 1‐2000 atm. The volume of activation is found to be ‐20.9 cm^3^/mole (CH~2~Cl~2~) and ‐24.5 cm^3^/mole (CH~3~CN). The estimated volume of the transition state is equal in both solvents and is of the same order of magnitude as the partial molar volume of the cycloadduct 1,1‐diethoxy‐2,2,3,3‐tetracyanocyclopentane. These findings are in agreement with a concerted cycloaddition mechanism via a weak complex of the reactants.