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Synthesis of optically active α,β‐disubstituted β‐amino nitriles and β‐amino acids starting from asparagine
Author(s) -
Gmeiner Peter,
Hummel Evi,
Haubmann Christian
Publication year - 1995
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.1995199511278
Subject(s) - chemistry , deprotonation , alkylation , nitrile , asparagine , amino acid , derivative (finance) , carbanion , optically active , stereochemistry , organic chemistry , ion , catalysis , biochemistry , financial economics , economics
Starting from the enantiomerically pure building block 2 which is readily available from D‐asparagine α,β‐disubstituted β‐amino nitriles and β‐amino acids could be synthesized. After deprotonation of the nitrile α‐position the introduction of substituents was performed by alkylation of either 2 or the TBDMS‐protected derivative 3. Starting from the β homoserine equivalent 2 the reaction proceeds via a dianionic intermediate resulting in a preferred formation of the threo ‐configured products 6a,b (ratio of isomers: 7:1). Modification of the side chain was demonstrated by displacement reactions with LiBH 4 or potassium thioacetate.