556828-91-2

Upstream product

• 67-56-1 methanol 
• 219826-09-2 2-methyl-4-(3-nitro-benzyl)-4H-oxazol-5-one 
• 99-61-6 3-nitro-benzaldehyde 
• 543-24-8 N-acetylglycine 

Downstream Products

• 219826-17-2 N-acetyl 3-C-(3,7-anhydro-4,5,6,8-tetra-O-acetyl-1,1,2,2-tetradehydro-1,2-D-glycero-D-mannooctityl)-DL-phenylalanine methyl ester 
• 219826-15-0 N-acetyl 3-C-(3,7-anhydro-4,5,6,8-tetra-O-acetyl-1,1,2,2-tetradehydro-1,2-D-glycero-D-gulooctityl)-DL-phenylalanine methyl ester 
• 219826-21-8 N-acetyl 3-C-(3,7-anhydro-4,5,6,8-tetra-O-acetyl-1,1,2,2-tetradehydro-1,2-D-glycero-D-talooctityl)-DL-phenylalanine methyl ester 
• 219826-19-4 N-acetyl 3-C-(3,7-anhydro-4,5,6,8-tetra-O-acetyl-1,1,2,2-tetradehydro-1,2-D-glycero-D-galactooctityl)-DL-phenylalanine methyl ester 
• 219826-13-8 N-acetyl-3-iodo-(DL)-phenylalanine methyl ester 

Relevant academic research and scientific papers

Ni(ii)-Catalyzed vinylic C-H functionalization of 2-acetamido-3-arylacrylates to access isotetronic acids

A ligand-free Ni(ii)-catalyzed cascade annulation reaction for the synthesis of 4-aryl-substituted isotetronic acids from 2-acetamido-3-arylacrylatesviavinylic C-H functionalization is reported. The reaction proceeds through heteroatom guided electrophilic insertion of nickel to the vinylic double bond followed by annulation with dibromomethane. This unconventional route features cascade steps, sole product formation, multiple functional group tolerance, low cost of catalysts and reagents, and readily available starting materials. Using this method, various aryl-substituted isotetronic acids have been synthesized which are biologically relevant. The annulation of 2-acetamido-3-arylacrylates has also been assessed with 1,2-dichloroethane, which resulted in the rearranged annulated products of 5-methyl substituted isotetronic acids.

Novel type of rigid C-linked glycosylacetylene-phenylalanine building blocks for combinatorial synthesis of C-linked glycopeptides

C-linked 3- and 4-(glycosylacetylene)-Fmoc-phenylalanines were synthesized as rigid building blocks for synthesis of libraries of neoglycopeptide templates. Perbenzylated 1,5-galactonolactone, 1,5- gluconolactone, and 1,5-mannonolactone were reacted with cerium TMS-acetylide and the products reduced to the C-glycosylacetylene-TMS derivatives. The gluco and galacto configurations yielded exclusively the β-C-glycoside, whereas the mannonolactone gave a mixture of α-C- and β-C-anomer. The products were subjected to acetolysis and TMS cleavage. The resulting peracetylated glycosylacetylenes were cross-coupled with the (R,S)-N(α)- acetyl-3- and 4-iodophenylalanine O-methyl esters by Pd(0) catalysis in piperidine to give the eight possible C-linked glycosyl amino acid building blocks 33-40 as diastereomeric pairs. These were O-deacetylated. As an example of further conversion into neoglycopeptide templates the N-acetyl group of the 4-linked galacto-diastereomeric pair 43 was hydrolyzed selectively by acylase 1 and separated from the (R)stereoisomer. The product was converted to 4-(β-C-galactosylacetylene)(N(α)-Fmoc-)-L-phenylalanine (52) by reaction with Fmoc-OSu. Acid hydrolysis of galactosyl acetylene phenyl alanine 43 at elevated temperature afforded the conversion of the acetylene to the 1'-oxo derivative which was also N(α)-Fmoc protected. The building blocks were used in the glycopeptide synthesis of three neoglycopeptide templates 54, 55, and 56 known to bind to murine MHC class II E(k) and to present the glycan for interaction with the T-cell receptor. This template has previously been employed to elicit a carbohydrate specific T- cell response.