Nitrobenzoxadiazole-labelled polyisoprenoid alcohols

Abstract

We have prepared, isolated, and characterized a series of nitrobenzoxadiazole labelled polyisoprenoid alcohols. The coupling reaction employed was a dicyclohexylcarbodiimide mediated condensation between a carboxylic acid derivative of nitrobenzoxadiazole and the polyisoprenoid alcohols citronellol, solanesol, and dolichol. Upon exposure to visible light, a self-sensitized singlet oxygen "ene" reaction oxidized double bonds in the isoprene moiety. The rate of oxidation is greatly reduced in solvents where singlet oxygen is short-lived. Key words: nitrobenzoxadiazole, isoprenoid, dolichol, citronellol, solanesol, fluorescence labelling, singlet oxygen, ene reaction.