Photochemistry of nitroso compounds in solution. IX. Steric effects in the photoaddition of N-nitrosodialkylamines to olefins. Magnetic non-equivalence of methylene protons caused by a distant asymmetry

Abstract

The photoreactions of various N-nitrosodialkylamines were studied in the presence of an olefin. Steric hindrance of the nitrosamino group could retard the efficiency of the addition. For N-nitroso-1,2,3,4-tetrahydroisoquinoline, the photodecomposition itself is so fast that no photoaddition takes place even in the presence of a reactive olefin such as styrene. The methylene group attached to the oximino group in IIa, IIIa, and VIa was magnetically non-equivalent, exhibiting AB quartet signals. The causes of this magnetic non-equivalence are discussed.