ChemInform Abstract: A MECHANISTIC STUDY OF THE PHOTODIMERIZATION OF FURO(3,2‐G)‐COUMARIN AND 2,3‐DIHYDROFURO(3,2‐G)‐COUMARIN DERIVATIVES

Abstract

Während die Photodimerisierung der Furocumarine (I) in Übereinstimmung mit theoretischen Voraussagen ausgehend von einem angeregten Triplett‐Zustand zu den Dimeren (II) führt, sind die Verhältnisse bei der Photodimerisierung der Dihydrofurocumarine (III) komplizierter.

Total Synthesis of a Cis-Syn 2-Carbomethoxypsoralen Furan-Side Thymidine Monoadduct

“…Attempts to synthesize these adducts in the absence of DNA have met with modest success. DNA helps to control the stereochemistry of the photochemical reaction because the hydrophobic psoralen molecule intercalates between the nucleobases resulting in primarily cis photoproducts; in addition, DNA also inhibits psoralen photodimerization . Two similar approaches to mimic the intercalation step involve irradiation of frozen aqueous solutions or evaporated thin films containing psoralen and thymidine …”

Frans De Schryver: Forty Years of Photochemistry and Photophysics

“…His interest in the photoinitiated polymerization switched to the photopolymerization using 2p + 2p-photocycloadditions of a,w-disubstituted alkanes with a focus on N,N'-alkylene dimaleimides, [1] biscoumarines [2] and bisanthracenes. [3] When elucidating the mechanistic aspects of those reactions, he extended the classical approach of the isolation and identification of photoreaction products with fluorescence and quenching experiments.…”

An Efficient Synthesis of a Furan-Side Furocoumarin Thymidine Monoadduct

“…The total synthesis of any psoralen−thymidine or furocoumarin−thymidine monoadduct has proved particularly difficult owing to the synthetically challenging cis -syn stereochemistry in the product. In the absence of a DNA helix, furocoumarins photodimerize adding an additional complication . Consequently, previous attempts to synthesize furocoumarin−thymidine monoadducts have resulted in photoproducts with the incorrect stereochemistry or a mixture of isomers from which only small quantities of the desired isomer could be isolated …”