
%0 Journal Article
%A Buckland, SJ 
%A Halton, B 
%A Stanovnik, B 
%T Studies in the Cycloproparene Series: Approaches to Cyclopropaheteroarenes
%J Australian Journal of Chemistry
%D 1987/12/01
%V 40
%N 12
%P 2037-2047
%K 
%R https://doi.org/10.1071/CH9872037
%U https://www.publish.csiro.au/paper/CH9872037 
%X Photolysis of the pyrazolopyridazines (3) results in the loss of nitrogen. The resultant diradicals (5) do not close to the cyclopropa [d]pyridazines (4) but undergo 1,4-hydrogen transfer to afford the 8-(2'-propenyl)pyridazines (6) instead. In the presence of trapping agents diradicals (5)give ethers (7) with methanol, epoxycyclohepta [d]pyridazines (8) with furan, and the 1,4- and 1,2-addition products (16) and (17) respectively, with butadiene. The formation of (8) and (16)provides the first examples of 1,4-addition of a 1,3-diradical to a diene. 
