Synthesis of N-protected N-methyl serine and threonine
摘要:
Two efficient and convenient synthesis of N-Cbz and N-Fmoc N-methyl serine and threonine an described. The amino acid side-chain alcohol can be protected as a TBDMS ether in very good yield or left free, followed by the formation and subsequent reduction of the corresponding oxazolidinone. (C) 2001 Published by Elsevier Science Ltd.
Synthetic studies on antifungal cyclic peptides, echinocandins. Stereoselective total synthesis of echinocandin D via a novel peptide coupling
作者:Natsuko Kurokawa、Yasufumi Ohfune
DOI:10.1016/s0040-4020(01)87959-x
日期:1993.7
Synthetic studies on the novel fungicidal oligopeptides, echinocandins (1b and 1c), are described. The constituent aminoacids 5–8 were synthesized in a stereocontrolled manner from the chiral starting materials, 5a, 6a and 7a, respectively. The coupling of these aminoacids was characterized by the use of unprotected aminoacid as the C-terminal and 2-pyridyl thiol ester as the N-terminal, and the
Direct asymmetric three-component organocatalytic anti-selective Mannich reactions in a purely aqueous system
作者:Lili Cheng、Xiaoyu Wu、Yixin Lu
DOI:10.1039/b701579h
日期:——
The direct three-componentMannichreactions of O-benzyl hydroxyacetone with p-anisidine and aromatic or aliphatic aldehydes in the presence of an L-threonine-derived catalyst afforded anti-1,2-amino alcohols in good-to-excellent yields and with enantioselectivities of up to 97%. This study is the first demonstration that direct three-componentMannichreactions can be promoted by a primary amino acid
Highlyenantioselectiveco-catalyticdirectaldolreactions by a combination of simple hydrophobic acyclicaminoacid and hydrogen-bonddonatingcatalysts are presented. The corresponding aldol products are formed in high yields with high regio-, diastereo- (anti or syn) and enantioselectivity (up to 99.5:0.5 er). The catalyst loadings can be decreased to as little as 2 mol%.
Highly Efficient Threonine-Derived Organocatalysts for Direct Asymmetric Aldol Reactions in Water
作者:Xiaoyu Wu、Zhaoqin Jiang、Han-Ming Shen、Yixin Lu
DOI:10.1002/adsc.200600564
日期:2007.4.2
The introduction of siloxy groups at the hydroxy function of natural threonine resulted in efficient hydrophobic organocatalysts, which could efficiently catalyze the direct aldolreactions of both cyclic and acyclic ketones with aromatic aldehydes in water with excellent enantiomeric excess.
Synthesis of monosaccharide analogues in an enantio‐ and diastereoselective manner has been investigated. Asymmetric benzoyloxylation and subsequent aldol reaction using two amine catalysts effectively give monosaccharide analogues with controlled three stereogenic centers.