15N nuclear polarization in the reactions of diallyl ether with nitrogen dioxide

Abstract

The reaction of diallyl ether with nitrogen dioxide in organic solvents yields a mixture of cis and trans 2,3-bis(nitromethyl)tetrahydrofurans, cis and trans 2-nitratomethyl-3-nitromethyltetrahydrofurans and a number of straight-chain compounds with one to four nitro groups. Under the conditions used, the cyclic compounds form the main products when the solution of nitrogen dioxide is slowly added to the solution of diallyl ether but not when the reverse mode of addition is used. When 15N-nitrogen dioxide is used, the products show strong 15N nuclear polarization: the 2,3-di(nitromethyl)tetrahydrofurans give an emission signal, and one straight-chain product with two nonequivalent nitro groups shows both an emission signal and an enhanced absorption signal. For both the cyclic and straight-chain products, the nuclear polarization is consistent with the successive reactions of diallyl ether with two nitrogen dioxide radicals with uncorrelated spins.Key words: diallyl ether, nitrogen dioxide, 15N nuclear polarization, CIDNP.