Iron-mediated radical nitro-cyclization reaction of 1,6-dienes.

Sequential steps that involved radical addition of a nitro group to 1,6-dienes promoted by the thermal decomposition of iron nitrate(III) nonahydrate, cyclization, and trapping of the resulting terminal radicals by a chlorine atom in the presence of chloride salt afforded five-membered-ring compounds. The present reaction provides a practical method for the synthesis of nitro compounds due to its simple experimental procedure and its use of nontoxic and inexpensive iron reagents.