Fluorescence properties of pseudomorphine and congeners: structure-activity relationships

The fluorescence properties of morphine congeners oxidized with potassium ferro-ferricyanide are described. Fluorescence did not occur in congeners with the following structural features: an alkyl or acyl group at the 3-O-position, a C-6 carbonyl group, or absence of the furan oxygen. Masking the carbonyl group by ethylene ketal formation effectively restored fluorescence. Morphine congeners that fluoresced were most sensitive to structural changes at C-6, C-7, anC-8. Details of effects of structural changes on emission maxima, intensity, and Stokes' shift are reported.