270089-67-3

Upstream product

• 3068-32-4 1-bromo-1-deoxy-2,3,4,6-tetra-O-acetyl-a-D-galactopyranoside 
• 82911-69-1 N-(9H-fluoren-2-ylmethoxycarbonyloxy)succinimide 
• 851857-30-2 (2S,5R)-2-Amino-6-benzyloxycarbonylamino-5-((2R,3R,4S,5S,6R)-3,4,5-triacetoxy-6-acetoxymethyl-tetrahydro-pyran-2-yloxy)-hexanoic acid 
• 3068-32-4 1-bromo-2,3,4,6-tetra-O-acetyl-D-galactopyranose 
• 504-91-6 (5R)-5-hydroxy-L-lysine 
• 25878-60-8 D-galactose pentaacetate 
• 501-53-1 benzyl chloroformate 
• 254757-67-0 (5R)-N^α-[(fluoren-9-yl)methoxycarbonyl]-N^ε-benzyloxycarbonyl-5-hydroxy-L-lysine allyl ester 

Relevant academic research and scientific papers

Mild oxidative cleavage of 9-BBN-protected amino acid derivatives

Protection of the amino acid moiety using 9-BBN is an effective method to enable side chain manipulations in synthesis of complex amino acids. We investigated the standard, mild method for deprotection of the 9-BBN group in methanolic chloroform, and found that it relies on a slow oxidation mediated by molecular oxygen. Building on this insight, we have developed a method that allows for a fast and selective deprotection using simple peroxy acid reagents. After Fmoc protection, products were isolated in >90% yield for a series of amino acid derivatives, including a galactosylated derivative of hydroxylysine. A representative set of 9-BBN-protected amino acid derivatives were efficiently deprotected using peracid reagents in excellent yields. Deprotection is orthogonal with several common protecting groups. Its tolerance of highly acid sensitive groups, such as trityl-protected amides and glycosidic linkages, is especially notable.

9-BBN as a convenient protecting group in functionalisation of hydroxylysine

9-BBN was used for regioselective protection of the α-amino and α-carboxyl groups of (5R)-5-hydroxy-L-lysine. The resulting 9-BBN complex was then employed in transformations such as N-Cbz protection, azido transfer, O-glycosylation, and O-silylation. Further manipulations led to improved methods for preparation of hydroxylysine and galactosylated hydroxylysine building blocks, suitable for direct use in peptide synthesis under standard Fmoc conditions.

An improved synthesis of a galactosylated hydroxylysine building block and its use in solid-phase glycopeptide synthesis

Different protective groups for (5R)-5-hydroxy-L-lysine were investigated in silver silicate promoted glycosylations with aceto- bromogalactose as glycosyl donor. Best results were obtained with Fmoc- Hyl(Cbz)-OAll, which was glycosylated in 80% yield. Re