Synthesis of tritium labelled thymic humoral factor γ2 (THF-γ2, thymoctonan)

The synthesis of the title compound labelled with tritium in the proline residue is reported. A five-step sequence starting from the commercially available [H-3]proline (1) under bar afforded [H-3]THF-gamma 2 with a radiochemical purity greater than or equal to 97% and high specific activity (>3.7 TBq/mmol). The overall radiochemical yield was about 15% from (1) under bar.