213619-68-2Relevant academic research and scientific papers
Asymmetric synthesis of α-Methyl α-Amino Acids through diastereoselective alkylation under mild reaction conditions of an iminic alanine template with a 1,2,3,6-Tetrahydro-2-Pyrazinone structure
Najera, Carmen,Abellan, Tomas,Sansano, Jose M.
, p. 2809 - 2820 (2007/10/03)
(6R)-6-Isopropyl-3-methyl-5-phenyl-1,2,3,6-tetrahydro-2-pyrazinone, obtained from (R)-valine and (S)-alanine, is highly diastereoselectively alkylated at room temperature by: a) activated alkyl halides under solid-liquid PTC conditions, b) non-activated alkyl halides with organic bases, c) electrophilic olefins employing both solid-liquid PTC conditions and organic bases, and d) allylic carbonates by means of palladium catalysis under neutral conditions. Enantiomerically pure (S)-α-methyl α-amino acids 8 are obtained by hydrolysis of the alkylated pyrazinones.
New chiral alanine template with a 1,2,3,6-tetrahydro-2-pyrazinone structure for the asymmetric synthesis of α-methyl α-amino acids
Abellan, Tomas,Najera, Carmen,Sansano, Jose M.
, p. 2211 - 2214 (2007/10/03)
(R)-6-Isopropyl-5-phenyl- 1,2,3,6-tetrahydro-2-pyrazinone, prepared from (R)-valine and (S)-alanine, reacts With activated alkyl halides and electrophilic olefins under solid-liquid PTC conditions: with K2CO3 as base, at room temperature and with high diastereoselectivity (>94%). The palladium-catalyzed allylation reaction of this alanine derivative under neutral conditions at room temperature also takes place with a de>96%. Final hydrolysis of alkylated pyrazinones affords enantiomerically pure α-methyl α-amino acids.
