Photocyclization of 2-alkoxy-3-alkyl phenyl ketones

ORGN 581

Yana Cen, Department of Chemistry, Michigan State University, East Lansing, MI 48823 and Peter J. Wagner, wagnerp@pilot.msu.edu, Chemistry Department, Michigan State University, East Lansing, Michigan, 48824.
o-Alkoxyphenyl ketones undergo slow d-hydrogen abstraction because the alkoxy prefers a conformation unfavorable for reaction. Blankespoor reported that a methyl group ortho to the alkoxy enhances the quantum yield for reaction of comparable quinones by changing the conformational equilibrium. This effect has been examined in 2-alkoxy-3-alkyl phenyl ketones for two reasons: 1) actual rate constants for triplet reaction can be measured as alkyl group is varied, the extent of their increase provides direct measures of conformational equilibria; 2) biradical geometries are also constrained, changes in product ratios can then be directly correlated with changes in geometry.
 

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