T. Kalai et al., CROSS-LINKING 2,5-DIHYDRO-1H-PYRROL-1-YLOXYL SPIN-LABEL REAGENTS BIFUNCTIONALIZED WITH AZIDOPHTHALIMIDYL AND METHYLTHIOSULFONYLOXY GROUPS, Synthesis, (10), 1994, pp. 1079-1082
Oxy-Cope and ortho ester Claisen rearrangements of 5- and 6-membered N
-oxyl radicals were carried out. The resulting more stable 5-membered
bromo derivative 6 was used in the synthesis of bifunctionalized cross
linking photo- and thiol-label 12.