%0 Generic
%A Li, Qiong
%A Yang, Shao-Bo
%A Zhang, Zhihui
%A Li, Lei
%A Xu, Peng-Fei
%D 2009
%T Diastereo- and Enantioselective Synthesis of β-Hydroxy-α-Amino Acids: Application to the Synthesis of a Key Intermediate for Lactacystin
%U https://acs.figshare.com/articles/dataset/Diastereo_and_Enantioselective_Synthesis_of_Hydroxy_Amino_Acids_Application_to_the_Synthesis_of_a_Key_Intermediate_for_Lactacystin/2876986
%R 10.1021/jo8023973.s007
%2 https://acs.figshare.com/ndownloader/files/4574848
%K Enantioselective
%K Diastereo
%K stereoselective
%K excess
%K diastereoselectivity
%K Application
%K Intermediate
%K acid
%K lithium
%K enolate
%K hydrolysis
%K Lactacystin
%K lactacystin
%K recovery
%K dr
%K presence
%K methodology
%K enantiomeric
%K equiv
%K chloride
%K Synthesi
%K Nucleophilic
%K aldehyde
%K 7.
%K ee
%K acidic
%K THF
%K aldol adducts
%K Hydroxy
%K auxiliary
%K tricyclic iminolactones 1
%K chiral auxiliaries 6
%K yield
%K preparation
%K isomers
%K synthesis
%K Acid
%K hydroxy
%X The development of a highly efficient and stereoselective methodology for the preparation of β-hydroxy-α-amino acids is described. Nucleophilic addition of enolates of tricyclic iminolactones 1a and 1b to aldehydes in the presence of 6 equiv of lithium chloride in THF at −78 °C leads to aldol adducts in good yield (63−86%) and high diastereoselectivity (up to >25:1 dr). Subsequently, hydrolysis of the aldol adducts under acidic conditions leads to the corresponding β-hydroxy-α-amino acids in good yields (up to 83%) and excellent enantiomeric excesses (99% ee) with good recovery yields of the chiral auxiliaries 6 and 7. This methodology was applied to the facile synthesis of the key intermediate for lactacystin along with several isomers.
%I ACS Publications