Photo-reorganization of 3-alkoxy-6-chloro-2-(thiophen-3-yl)-4H-chromen-4-ones: Regioselective cyclization via γ-hydrogen abstraction
摘要:
Regioselective photocyclization of 3-alkoxy-6-chloro-4H-chromen-4-ones bearing thiophen-3-yl moiety at 2-position has been described. These chromenones on irradiation by the pyrex filtered UV-light produced a diverse array of novel angular tetracyclic photoproducts. Of these, mostly the cyclic dihydro and dehydrogenated photoproducts had the gem-dihydro functionality and exocyclic double bonds onto the fused pyran ring respectively, which is unprecedent in these chromenones. (C) 2011 Elsevier B.V. All rights reserved.
Photo-reorganization of 3-alkoxy-6-chloro-2-(thiophen-3-yl)-4H-chromen-4-ones: Regioselective cyclization via γ-hydrogen abstraction
作者:Ramesh C. Kamboj、Rita Arora、Dinesh Kumar、Geeta Sharma
DOI:10.1016/j.jphotochem.2011.04.002
日期:2011.5
Regioselective photocyclization of 3-alkoxy-6-chloro-4H-chromen-4-ones bearing thiophen-3-yl moiety at 2-position has been described. These chromenones on irradiation by the pyrex filtered UV-light produced a diverse array of novel angular tetracyclic photoproducts. Of these, mostly the cyclic dihydro and dehydrogenated photoproducts had the gem-dihydro functionality and exocyclic double bonds onto the fused pyran ring respectively, which is unprecedent in these chromenones. (C) 2011 Elsevier B.V. All rights reserved.
Regioselective Photocyclization Reactions of 3-Allyloxy-6-chloro-2-(thiophen-3-yl)-4<i>H</i>-chromen-4-one: Solvent Effect
作者:Ramesh C. Kamboj、Dinesh Kumar、Rita Arora、Surinder Berar、Geeta Sharma
DOI:10.1002/jhet.1006
日期:2013.2
photo-irradiation of thienylchromenone resulted in the regioselective cyclization which is exclusively controlled by the nature of solvent used as reaction medium. Compared to nonpolar medium, polar solvent furnished a diverse array of novel angular tetracyclic photoproducts with gem-dihydro functionality and exocyclic double bonds on the fused pyran ring, which is unprecedented to best of our knowledge