A new synthetic route for the quorum sensing signal Autoinducer-2 (AI-2) is described and used for the preparation of [4-13C]-AI-2 starting from [1-13C]-bromoacetic acid. The key step in this process was the enantioselective reduction of an intermediate ketone. This synthesis provides, selectively, both enantiomers of the labelled or unlabelled parent compound, (R) or (S)-4,5-dihydroxypentane-2,3-dione (DPD) and was used for an improved synthesis of [1-13C]-AI-2.
