1158840-53-9

Upstream product

• 18107-18-1 diazomethyl-trimethyl-silane 

Downstream Products

• 1158840-64-2 para-methoxyphenyl 2-O-benzyl-4,6-benzylidene-4-O-[methyl (ethyl 2-O-benzyl-3,4-O-[2',3'-dimethoxybutane-2',3'-diyl]-α-D-mannopyranosyluronate)]-β-D-galactopyranoside 
• 1158840-66-4 methyl 2,3-di-O-benzyl-4-O-[methyl (ethyl 2-O-benzyl-3,4-O-[2',3'-dimethoxybutane-2',3'-diyl]-α-D-mannopyranosyluronate)]-β-D-mannopyranosyluronate 
• 1158840-72-2 methyl 2,3,4-tri-O-benzyl-6-O-[methyl (ethyl 2-O-benzyl-3,4-O-[2',3'-dimethoxybutane-2',3'-diyl]-α-D-mannopyranosyluronate)]-α-D-glucopyranoside 
• 1158840-63-1 methyl 2,3,4-tri-O-benzyl-6-O-[methyl (ethyl 2-O-benzyl-3,4-O-[2',3'-dimethoxybutane-2',3'-diyl]-α-D-mannopyranosyluronate)]-α-D-glucopyranoside 
• 1158840-71-1 C₂₁H₂₇F₃O₁₁S 

Relevant academic research and scientific papers

Stereoselectivity of glycosylations of conformationally restricted mannuronate esters

Glycosidation of conformationally unrestricted mannuronate ester donors proceeds in a highly β-selective fashion, whereas condensations of mannuronate ester donors, which are conformationally constrained by a 3,4-butanedimethylacetal or a 2,3-isopropylidene function, provide α-selective products. We hypothesize that the difference in stereochemical outcome of these condensations results from the different conformations of the product forming oxacarbenium intermediate. The formation of the β-linked products from the flexible mannuronates is thought to originate from the most favorable 3H4 oxacarbenium ion, which is not accessible from the conformationally restrained donors. Although an α-triflate intermediate is formed upon activation of the 3,4-butanedimethylacetal protected mannuronate ester thio donor, this is not the product forming intermediate. The anomeric triflate serves as a reservoir for the 4H3 oxacarbenium ion, which is glycosidated to provide the α-linked mannuronates.