[EN] BETA-SECRETASE INHIBITING COMPOUNDS HAVING OXO-DIHYDRO-PYRAZOLE MOIETY<br/>[FR] COMPOSÉS INHIBITEURS DE LA BÉTA-SÉCRÉTASE CONTENANT UN FRAGMENT D'OXO-DIHYDRO-PYRAZOLE
申请人:LG LIFE SCIENCES LTD
公开号:WO2009038411A3
公开(公告)日:2009-05-07
Chiral ligands containing heteroatoms. 11. Optically active 2-hydroxymethyl piperazincs as catalysts in the enantioselective addition of diethylzinc to benzaldehyde
(2R,5S) and (2S,5S)-2-hydroxymethyl-5-alkyl piperazines 1–5 were prepared in good yields without any racemization. The use of these compounds as chiral catalysts for the enantioselectiveaddition of diethylzinc to aldehydes is described. This paper reports the first example of the use of piperazine methanols in asymmetric synthesis.
General and convenient syntheses of optically active 5-alkylpiperazine-2-carboxylic acids are described. The methods are based on cyclization of L- or D-serine with α-amino acids and occur without loss of optical purity. The presented procedures are based on readily available starting materials and can be arranged for multigram quantities.