Total Synthesis and Absolute Configuration of the Natural Amino Acid Tetrahydrolathyrine

The natural product tetrahydrolathyrine has been synthesized through an iminoiodane-mediated aziridination of a (2S)-allylglycinol derivative, which provided a 2:3 mixture of diastereoisomers. One of these diastereoisomers was converted to the natural product and the other to its C-4 epimer. The C-4 configuration was established from NOESY NMR analysis and X-ray structure of compounds derived from the non-natural diastereoisomer. Thus, tetrahydrolathyrine was shown to have the (2S,4R) absolute configuration.