Synthesis of Enantiopure <i>syn</i>-β-Amino Alcohols. A Simple Case of Chelation-Controlled Additions of Diethylzinc to α-(Dibenzylamino) Aldehydes
作者:José M. Andrés、Roberto Barrio、María A. Martínez、Rafael Pedrosa、Alfonso Pérez-Encabo
DOI:10.1021/jo960017t
日期:1996.1.1
Enantiomerically pure syn-2-amino alcohols 6 are prepared by addition of diethylzinc to chiral alpha-(dibenzylamino) aldehydes 4. The addition is highly stereoselective, leading to syn-2-(dibenzylamino) alcohols 5 with excellent diastereomeric excesses (76-98%). Debenzylation of 5 by hydrogenolysis on Pearlman's catalyst yields quantitatively the amino alcohols 6.
对映体纯的顺式-2-氨基醇6是通过将二乙基锌加到手性α-(二苄基氨基)醛4上而制备的。该加成物具有高度的立体选择性,从而制得具有出色的非对映异构体过量的顺式2-(二苄基氨基)醇5(76-98 %)。通过在Pearlman催化剂上进行氢解将5脱苄基化,可定量得到氨基醇6。