Intramolecular Photochemical Cycloaddition of Nonconjugated Olefins

Photosensitized isomerization of norbornadiene for solar energy storage and supression of side reaction.

“…One is the use of suitable photosensitizers which assist the photoisomerization of norbornadiene to quadricyclene.1'10"12'18'25"27* The other is the introduction of appropriate substituents into norbornadiene to extend the absorption band to longer wavelength. [3][4][5][6][7]16,19,20,23,29,32) But the laUer way hag such demerits as reduction of quantum yield, decrease in the amount of energy stored because of the increase in molecular weight, and increase of material cost owing to the complication of synthesis. Although the former state^S -^S), the photosensitizer molecule undergoes non-radiative intersystem crossing from singlet to triplet state (3S), and then transfers the energy to norbornadiene.…”

ORGANIC PHOTOCHEMISTRY—XV. APPLICATIONS OF PHOTOCYCLOADDITION REACTIONS IN NATURAL PRODUCT SYNTHESES*,†

“…The facility of these two types of reactions is now well understood on the basis of orbital of the natural chemist,s of recently, the last thetic tools. This review focuses on those photocycloaddition reactions which have been used in the total Dilling et al (1976 valence isomerization of a conjugated diene is not considered a photocycloaddition reaction (Dilling, 1966;Dilling, 1969). Two types of four-membered rings, cyclobutanes 1 and oxetanes 2, have been generated in the course of these synthetic sequences (Scheme 1).…”

Photochemistry of bioactive compounds. Major photolytic product of endrin

“…Effects of sunlight and laboratory ultraviolet light on pesticides have been investigated with renewed interest in the past decade, due in part to the exciting advances in the field of organic photochemistry (Dilling, 1966). Mitchell (1961) reported that two cyclodiene insecticides, Dieldrin (I) and Aldrin (II), were decomposed by irradiation at 253.7 nm.…”