Reaction of dinitrogen trioxide with 2-methylpropene and other alkenes. Evidence for electrophilic nitrosation

The solid dimer product from the reaction of dinitrogen trioxide and 2-methylpropene was converted to the corresponding oxime by heating with or without a solvent for ca. 2 days. This establishes the orientation of the dinitrogen trioxide addition product as the 1-nitroso- rather than the 2-nitroso-compound as previously thought. A number of other alkene–dinitrogen trioxide adducts have been prepared; most were shown by i.r. spectroscopy to exist partially in the oxime form, the fraction of oxime increasing on warming or on standing for a long time. Hydrolysis of two of the adducts gave products which were in accord with the suggested orientation. There was a striking analogy between these results and those obtained by other workers who examined the products of addition of dinitrogen tetraoxide (acting as nitrosonium nitrate) with alkenes, and their hydrolysis products.