PHOTO-OXIDATION OF DIMETHYLTHYMINE - CONTRASTING REGIOSPECIFIC AND STEREOSPECIFIC REACTIONS OF THE INITIAL PHOTOPRODUCT WITH NUCLEOPHILES

Postirradiation treatment of photooxidized 1, 3-dimethylthymine with phenol resulted in the formation of the unexpected carbon-carbon coupling products, cis-5-hydroxy-6-[p- or o-hydroxyphenyl]-l, 3-dimethyl-5, 6-dihydrothymine (6a and 6b), rather than the anticipated 6-phenoxy adduct analogous to the products observed with other oxygen and sulfur nucleophiles, thus indicating two different mechanistic pathways for ring opening of the initial epoxide which may be of significance in chemical reactions of biological importance. © 1979, American Chemical Society. All rights reserved.