1094673-91-2

Upstream product

• 120230-41-3 N-(9-phenylfluoren-9-yl)-L-aspartic acid α-t-butyl β-methyl diester 
• 74-88-4 methyl iodide 

Downstream Products

• 120230-46-8 tert-butyl (2S,3S)-2-<(9-phenylfluorenyl)amino>-3-methyl-4-hydroxybutanoate 
• 120230-47-9 tert-butyl (2S,3R)-2-<(9-phenylfluorenyl)amino>-3-methyl-4-hydroxybutanoate 
• 120230-56-0 (2S,3S)-tert-butyl 2-(benzyloxycarbonylamino)-4-hydroxy-3-methylbutanoate 
• 120262-55-7 tert-butyl (2S,3R)-2-<(benzoxycarbonyl)amino>-3-methyl-4-hydroxybutanoate 
• 120230-58-2 (2S,3S)-2-Benzyloxycarbonylamino-3-methyl-4-oxo-butyric acid tert-butyl ester 
• 120230-57-1 tert-butyl (2S,3R)-2-<(benzoxycarbonyl)amino>-3-methyl-4-oxobutanoate 
• 120230-60-6 (S)-2-((3S,4S)-3-Benzyloxycarbonylamino-4-methyl-2-oxo-pyrrolidin-1-yl)-propionic acid methyl ester 
• 120328-49-6 (S)-2-((3S,4R)-3-Benzyloxycarbonylamino-4-methyl-2-oxo-pyrrolidin-1-yl)-propionic acid methyl ester 
• 120230-48-0 tert-butyl (2S,3S)-2-<(9-phenylfluorenyl)amino>-3-methyl-4-oxobutanoate 
• 120230-48-0 tert-butyl (2S,3R)-2-<(9-phenylfluorenyl)amino>-3-methyl-4-oxobutanoate 
• 120329-59-1 (2S,3R)-2-Benzyloxycarbonylamino-4-((S)-1-methoxycarbonyl-ethylamino)-3-methyl-butyric acid tert-butyl ester 
• 120230-59-3 (2S,3S)-2-Benzyloxycarbonylamino-4-((S)-1-methoxycarbonyl-ethylamino)-3-methyl-butyric acid tert-butyl ester 
• 120230-49-1 (2S,3R)-4-((S)-1-Methoxycarbonyl-ethylamino)-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)-butyric acid tert-butyl ester 
• 120230-49-1 (2S,3S)-4-((S)-1-Methoxycarbonyl-ethylamino)-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)-butyric acid tert-butyl ester 

Relevant academic research and scientific papers

Total synthesis of the large non-ribosomal peptide polytheonamide B

Polytheonamide B is by far the largest non-ribosomal peptide known at present, and displays extraordinary cytotoxicity (EC50 =68 pg ml -1 , mouse leukaemia P388 cells). Its 48 amino-acid residues include a variety of non-proteinogenic d- and l-amino acids, and the absolute stereochemistry of these amino acids alternate in sequence. These structural features induce the formation of a stable β-strand-type structure, giving rise to an overall tubular structure over 30A? in length. In a biological setting, this fold is believed to transport cations across the lipid bilayer through a pore, thereby acting as an ion channel. Here, we report the first chemical construction of polytheonamide B. Our synthesis relies on the combination of four key stages: syntheses of non-proteinogenic amino acids, a solid-phase assembly of four fragments of polytheonamide B, silver-mediated connection of the fragments and, finally, global deprotection. The synthetic material now available will allow studies of the relationships between its conformational properties, channel functions and cytotoxicity.

Native chemical ligation at valine: A contribution to peptide and glycopeptide synthesis

(Chemical Equation Presented) A Val-uable link: The title transformation is achieved by a two-step ligation, radicalbased desulfurization strategy (see scheme; NCL=native chemical ligation). After S→N acyl transfer, in which the acyl acceptor is a γ-thiol valine derivative, and site-specific dethiolation, a valine residue appears at the site of ligation. This method accomplishes ligations at Thr-Val and Pro-Val sites, and allows successful ligation of glycopeptide fragments.

Conformationally Constrained Peptides. Chirospecific Synthesis of 4-Alkyl-Substituted γ-Lactam-Bridged Dipeptides from L-Aspartic Acid

The synthesis of enantiomerically pure γ-lactam-bridged dipeptide analogues of Val-Ala, Ile-Ala, and β-MeLeu-Ala starting from L-aspartic acid is presented.N-(9-Phenylfluorenyl)-L-aspartic acid α-tert-butyl β-methyl diester and N-(9-Phenylfluorenyl)-L-asp