A New Reaction of Ethylenic Double Bonds

IN prosecuting our researches on the chemistry of nitrile oxides R —C ≡ N→O, a class of compounds closely related to aliphatic diazo-compounds R —CH : N 2 and diazo-imides R —N 3 1 , we have found that benzonitrile oxide (I) in ethereal solution reacts easily, at ordinary temperature or on slight heating, with the double bonds of ethylenic derivatives, to give Δ 2 -isoxazolines (II): exactly in the same way that aliphatic diazo-compounds and diazo-imides combine with ethylenic derivatives yielding respectively pyrazolines and dihydro-triazoles.