Photochemical Rearrangement of 8- methyl Spiro [2.5] oct-7-en-4-one to 4-methyl Spiro [2.5] oct-4-en-6-one

Abstract

Irradiation of &methyl spiro [2.5] oct-7-en-4-one through its singlet excited state resulted in the formation of 4-methyl spirO [2.5] oct-4-en -6-one. We have used the cyclopropyl moiety in the molecule as a probe to study the operating mechanism in the photochemistry of ?, ?-unsaturated compounds. The results showed that this photoisomerization probably occurs through a concerted process.