Orientation of azide addition to homoconjugated dienes

Abstract

The 1,3-dipolarcycloaddition of phenyl azide to bicyclic dienes 8-10 proceeds readily at the angle strained double bond to give both 1,2,3-A2-triazoline isomers which would result from the two possible orientations of addition. The major triazoline isomer in each case is that resulting from stabilization of the dipolar transition state by the neighboring unreactive double bond. The structures of the triazolines were deduced from their nuclear magnetic resonance spectra in CCI,, CDCl,, and CsH6.