Photostimulated free radical-tethered intramolecular cyclization reaction towards α-tetralones and their analogues

ORGN 606

Byeong Hyo Kim, bhkim@kw.ac.kr1, Rongbi Han1, Insik Jeon, bhkim@daisy.kwangwoon.ac.kr1, Bong Kwan Soh1, Young Moo Jun1, and Byung Min Lee, bmlee@pado.krict.re.kr2. (1) Department of Chemistry, Kwangwoon University, 447-1 Nowon-ku Wolgye-dong, Seoul, 139-701, South Korea, (2) Korea Research Institute of Chemical Technology, 100 yousung-ku jang-dong, Taejon, 305-600, South Korea
By applying oxidative alkylation processes through the photolysis of the alkylmercury chloride/DABCO with electron-deficient aromatics, heteroatomic aromatics, or coumarin derivatives that have olefinic groups in the same molecule, the cyclization towards the aromatic ring (or electron-deficient olefin) would be possible via free radical tethered reaction. Thus, photostimulated tethered free radical reactions for the intramolecular cyclizations towards α-tetralones, N-containing α-tetralone analogues, 3,4,4a,10b-tetrahydro-2H-pyrano[3,2-c]chromen-5-ones, and 2,3,4,4a,6,10b-hexahydropyrano[3,2-c]quinolin-5-one were investigated. Photolysis of the t-BuHgX/Dabco with 1-aryl-4-penten-1-ones produced α-tetralones via tert-butyl radical attacks on the terminal, in situ-formed secondary radical attack to the aromatic ring, proton abstraction and electron transfer from the radical anion intermediate to t-BuHgX. At a similar photolysis condition, it was also successful for the formation of N-containing a-tetralone analogues, 3,4,4a,10b-tetrahydro-2H-pyrano[3,2-c]chromen-5-ones, and 2,3,4,4a,6,10b-hexahydropyrano[3,2-c]quinolin-5-one in reasonable yields.
 

Asymmetric Reactions, Heterocycles, Aromatics, Combinatorial, and Physical Organic Chemistry
8:00 PM-10:00 PM, Wednesday, 31 August 2005 Washington DC Convention Center -- Hall A, Poster

Division of Organic Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005