The Ene Reaction of Singlet Oxygen with Olefins

Abstract

The reactions of singlet oxygen (¹O₂) with cis and trans butenes-1,1,1-d₃, at—80°C in Freon-11, show a product isotope effect (k_H/k_D) of 1.38 and 1.25 respectively. Isomerization of the starting materials or formation of dioxetanes were not observed during the course of the photooxygenation. Together with the isotope effects on the reactions of tetramethylethylene-d₆ isomers with singlet oxygen, these results require the reversible formation of a perepoxide or charge transfer intermediate.

Key Words:

• Singlet oxygen
• ene reaction
• mechanism of cis-butene-1,1,1,-d₃
• trans-butene-1,1,1,-d₃