A New Method for the Synthesis of (S)-α-Methylisoserine and Its Incorporation into Peptides
作者:Raul Pires、Klaus Burger
DOI:10.1055/s-1996-4387
日期:1996.11
(S)-(+)-Citramalic acid is converted into isocyanate 4 using hexafluoroacetone as the protecting agent. Isocyanate 4 represents a doubly activated species, which upon reaction with alcohols provides N-protected, carboxyl-activated α-methylisoserine derivatives, perfectly suited for peptide synthesis (5 → 8). Acylation of 4 with N-protected amino acids gives fully protected carboxyl-activated dipeptides. Ring opening with amino acid esters results in the formation of tripeptides (9 → 10).
S<sub>N</sub>2 vs. E2 on quaternary centres: an application to the synthesis of enantiopure β<sup>2,2</sup>-amino acids
作者:Alberto Avenoza、Jesús H. Busto、Francisco Corzana、Gonzalo Jiménez-Osés、Jesús M. Peregrina
DOI:10.1039/b400282b
日期:——
SN2 and E2 competing reactions in cyclic sulfamidates can be modulated by the change of an amide group to an ester group attached to the quaternary carbon activated for the nucleophilic attack, allowing an easy approach to enantiopure α,α-disubstituted β-amino acids.
Stereocontrolled Ring-Opening of a Hindered Sulfamidate with Nitrogen-Containing Aromatic Heterocycles: Synthesis of Chiral Quaternary Imidazole Derivatives
作者:Lara Mata、Gonzalo Jiménez-Osés、Alberto Avenoza、Jesús H. Busto、Jesús M. Peregrina
DOI:10.1021/jo200479y
日期:2011.5.20
α-methylisoserine as an electrophile in a nucleophilic displacement reaction with nitrogen-containing aromatic heterocycles. Several imidazoles and pyrazole were tested as nucleophiles in the absence of an additional base to give the corresponding ring-opening compounds. We show that the process takes place by inversion of the configuration of the quaternary electrophilic center, retaining the enantiomeric excess
Synthesis of β<sup>2,2</sup>-Amino Acids by Stereoselective Alkylation of Isoserine Derivatives Followed by Nucleophilic Ring Opening of Quaternary Sulfamidates
作者:Pablo Tovillas、Claudio D. Navo、Paula Oroz、Alberto Avenoza、Francisco Corzana、María M. Zurbano、Gonzalo Jiménez-Osés、Jesús H. Busto、Jesús M. Peregrina
DOI:10.1021/acs.joc.2c01034
日期:2022.7.1
O-acetalization/intramolecular transcarbamoylation reaction between conveniently protected l-isoserine and 2,2,3,3-tetramethoxybutane. The delicate balance of the steric interactions between the different functional groups on each possible diastereoisomer controls their thermodynamic stability and hence the experimental product distribution. These chiral isoserine derivatives undergo diastereoselective alkylation
作者:Alberto Avenoza、Jesús H. Busto、Francisco Corzana、Gonzalo Jiménez-Osés、Miguel Parı́s、Jesús M. Peregrina、David Sucunza、Marı́a M. Zurbano
DOI:10.1016/j.tetasy.2003.09.051
日期:2004.1
Herein we describe the synthesis of the two enantiomerically pure 3-amino-2-hydroxy-2-methylpropionic acids-(S)- and (R)-alpha-methyl isoserines-starting from the chiral diols (S)- and (R)-2,3-dihydroxy-N-methoxy-2,N-dimethylpropionamides, respectively, which were obtained by Sharpless asymmetric dihydroxylation (AD) of the olefin N-methoxy-2,N-dimethylacrylamide with AD-mix alpha or beta as chiral catalytic ligands. (C) 2003 Elsevier Ltd. All rights reserved.