Addition of Chiral Glycine, Methionine, and Vinylglycine Enolate Derivatives to Aldehydes and Ketones in the Preparation of Enantiomerically Pure ?-Amino-?-Hydroxy Acids
作者:Dieter Seebach、Eusebio Juaristi、David D. Miller、Christof Schickli、Theodor Weber
DOI:10.1002/hlca.19870700129
日期:1987.2.4
alcohols in excellent yields (see Scheme 5). Furthermore, the addition to aldehydes proceeds with high diastereoselectivity to give, after acid hydrolysis, threo-α-amino-β-hydroxy acids of high enantiomeric purity. Some of the threo-α-amino-β-hydroxy acids prepared in this work are the proteinogenic (S)-threonine (26), the naturally occurring (S)-3-phenylserine (28), and (S)-3-hydroxyleucine (27) as
GANDER-COQUOZ, MARLYSE;SEEBACH, DIETER, HELV. CHIM. ACTA, 71,(1988) N 1, 224-236
作者:GANDER-COQUOZ, MARLYSE、SEEBACH, DIETER
DOI:——
日期:——
N,O-Acetals from Pivalaldehyde and Amino Acids for the ?-Alkylation with Self-Reproduction of the Center of Chirality. Enolates of 3-Benzoyl-2-(tert-butyl)-1,3-oxazolidin-5-ones
作者:Dieter Seebach、Antoine Fadel
DOI:10.1002/hlca.19850680521
日期:1985.8.14
The sodium salts of (S)-alanine, (S)-phenylalanine, (S)-valine, and (S)-methionine are condensed with pivalaldehyde to imines 5. Cyclization by treatment with benzoyl chloride in cold CH2Cl2 gives mainly (4:1 to > 99:1) the (2S,4S)-4-alkyl-3-benzoyl-2-(tert-butyl)-1,3-oxazolidin-5-ones (6; cis-configuration) in high yields (85–95%). The oxazolidinones 6 and 7 are deprotonated with lithium diethylamide