A. Kpissay et al., EVIDENCE FOR AZIDYL RADICAL-INITIATED OLEFIN ISOMERIZATION - ONE-WAY ISOMERIZATION OF (Z)-UROCANIC ACID, Tetrahedron letters, 38(49), 1997, pp. 8435-8438
(Z)-Urocanic acid (cis-UA), unlike its (E) isomer (trans-UA), undergoe
s photoisomerization in the presence of nitro blue tetrazolium (NBT2+)
and sodium azide. Evidence is presented that the photoisomerization i
nvolves the reversible addition of the azidyl radical to the double bo
nd. (C) 1997 Elsevier Science Ltd.