A facile synthesis of enantiomerically pure 1-(piperazin-2-yl)ethan-1-ol derivatives from (2s,3r)-threonine

Article abstract of DOI:10.1055/s-1999-3596

Starting from the proteinogenic amino acid (2S,3R)-threonine (4) a novel method for the preparation of enantiomerically pure 1-(1-benzylpiperazin-2- yl)ethan-1-ols with various substituents in position 4 (15 - 20) is described. The sequence involves as key step the LiAlH₄ reduction of the bicyclic piperazinediones 11a,b-14a,b which establishes the 1-benzyl protective group and simultaneously liberates the 1-hydroxyethyl side chain for further transformations.