S. Soukara et B. Wunsch, A facile synthesis of enantiomerically pure 1-(piperazin-2-yl)ethan-1-ol derivatives from (2S,3R)-threonine, SYNTHESIS-S, (10), 1999, pp. 1739-1746
Starting from the proteinogenic amino acid (2S,3R)-threonine (4) a novel me
thod 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 p
iperazinediones 11a,b-14a,b, which establishes the l-benzyl protective grou
p and simultaneously liberates the l-hydroxyethyl side chain for further tr
ansformations.