Abstract
The mechanisms of the three primary processes in the vapor phase photolysis of 1,3-butadiene have been investigated by the use of deuterium labeling on the end carbon atoms. None of the processes proceeds by the obvious pathway exclusively. Thus ethylene and acetylene are formed not only by a 1,3 shift but also via an intermediate cyclobutene and a third path which gives C2H2D2 and C2D2. Two mechanisms seem to be applicable to the other two primary processes which give 1,2-butadiene and H2 + C4H4, respectively. © 1966, American Chemical Society. All rights reserved.