FREE-RADICAL CYCLIZATION OF PETROSELINIC ACID

Petroselinic acid was cyclized via methyl 2-iodopetroselinate (1) with tributyltin hydride to give methyl trans- and cis-2-dodecyl-1-cyclopentanecarboxylate (2). The atom-transfer method with hexabutylditin resulted in the formation of bicyclic gamma-lactones 4 and methyl trans-2-(1'-iodododecyl)-1-cyclopentanecarboxylate (trans-5). The same products were obtained with the new initiator system SnCl2/AgOAc. This method showed, if compared with the other methods, the shortest reaction time, the highest yield and stereoselectivity combined with a very simple workup procedure and the use of less toxic chemicals.