Synthesis of [H-3] and [C-14]genipin

Abstract

[H-3]Genipin was synthesized in a single step by Ir(I) catalyzed hydrogen isotope exchange. Conditions for selective exchange of the sp(2) CH bond ortho to the methyl ester functionality were developed through deuterium modeling studies through a catalyst screen. Optimized conditions so obtained were then utilized with tritium gas to generate [H-3]genipin at a specific activity of 18.5 Ci/mmol. Racemic [C-14]genipin was prepared in eight steps in overall 5.4% radiochemical yield from potassium [C-14]cyanide.