Journal of Photosciences

Photocyclization Reactions of (ω-Phthalimidoalkoxy)acetic Acids via Sequential Single Electron Transfer-Decarboxylation Pathways

Volume 7(2000), 143-148 page

저자: Ung Chan Yoon, Chan Woo Lee, Sun Wha Oh, Hyun Jin Kim and Sang Jin Lee

   7-4-143.pdf (89.8K)

Keywords: photocyclizations  (ω-phthalimidoalkoxy)acetic acids  sequential single electron transferdecarboxylation pathway


Studies have been conducted to explore single electron transfer (SET) promoted photocyclization reactions of (ω-phthalimidoalkoxy)acetic acids(alkoxy=ethoxy, n-propoxy and n-butyloxy).
Photocyclizations occur in methanol or acetone in high yields to produce cyclized products in which phthalimide carbonyl carbon is bonded to the carbon of side chain in place of the carboxylic group.
These photocyclizations are thought to proceed through pathways involving intramolecular SET from oxygen in the α-carboxymethoxy groups to the singlet excited state phthalimide moieties followed by decarboxylation of the intermediate α-carboxymethoxy cation radicals and cyclizations by radical coupling.
The photocyclizations occur ca. three times faster in both methanol or acetone with one equivalent of sodium hydroxide added to the reactions and occur slower in acetone than in methanol.
The efficient and regioselective cyclization reactions observed for photolyses in methanol represent synthetically useful processes for construction of heterocyclic compounds.