Please use this identifier to cite or link to this item:
http://repository.kln.ac.lk/handle/123456789/3793
Title: | Photochemical Triggering of the Bergman and Myers?Saito Cyclizations |
Authors: | Pandithavidana D R Kuzmin A Popik V V |
Issue Date: | 2010 |
Publisher: | Australian Journal of Chemistry |
Abstract: | Two strategies for the photochemical generation of reactive enediyne compounds and their subsequent cycloaromatization to p-benzyne or ?,3-didehydrotoluene derivatives are discussed in this account. The first method employs a photo-Wolff reaction of stable 11- or 12-membered ring precursor enediynes containing the 2-diazo-1,3-diketone moiety. Irradiation of these compounds results in ring contraction and the formation of two isomeric enediynes possessing an enolized ?-ketoester fragment. One of the isomers undergoes the conventional Bergman cyclization, whereas the other isomerizes into the enyne-allene tautomer, which rapidly cyclizes via a Myers?Saito mechanism. The second strategy consists of replacing the triple bond in a cyclic enediyne or enyne-allene structure with a cyclopropenone group, rendering them thermally stable. Photolysis of cyclopropenones results in efficient decarbonylation and the regeneration of a triple bond, restoring the enediyne ?-system. The generation of reactive enediynes by non-resonant two-photon excitation using wavelengths within a ?phototherapeutic window? was also demonstrated. Photogenerated enediynes show significant nuclease activity, efficiently inducing single-strand dDNA cleavage. |
URI: | http://repository.kln.ac.lk/handle/123456789/3793 |
Appears in Collections: | Chemistry |
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.