254444-23-0

Upstream product

• 1125-88-8 benzaldehyde dimethyl acetal 
• 100-39-0 benzyl bromide 
• 136882-36-5 2-((2S,3R,4R,5S,6R)-4,5-Dihydroxy-6-hydroxymethyl-2-phenylsulfanyl-tetrahydro-pyran-3-yl)-isoindole-1,3-dione 
• 86520-63-0 2,3,4,6-tetra-O-acetyl-α-galactopyranosyl trichloroacetimidate 
• 159734-70-0 phenyl 3,6-di-O-benzyl-2-deoxy-2-phthalimido-1-thio-β-D-glucopyranoside 

Relevant academic research and scientific papers

Regio/Stereoselective Glycosylation of Diol and Polyol Acceptors in Efficient Synthesis of Neu5Ac-α-2,3-LacNPhth Trisaccharide

A concise approach to a Neu5Ac-α-2,3-LacNPhth trisaccharide derivative was developed. First, the regio/stereoselective glycosylation between glycoside donors and glucoNPhth diol acceptors was investigated. It was found that the regioselectivity depends not only on the steric hindrance of the C2-NPhth group and the C6-OH protecting group of the glucosamine acceptors, but also on the leaving group and protecting group of the glycoside donors. Under optimized conditions, LacNPhth derivatives were synthesized in up to 92 % yield through a regio/stereoselective glycosylation between peracetylated-α-galactopyranosyl trichloroacetimidate and p-methoxyphenyl 6-O-tert-butyldiphenylsilyl-2-deoxy-2-phthalimido-β-d-glucopyranoside, avoiding the formation of glycosylated orthoesters and anomeric aglycon transfer. Then, the LacNPhth derivative was deacylated and then protected on the primary position by TBDPS to form a LacNPhth polyol acceptor. Finally, the Neu5Ac-α-2,3-LacNPhth derivative was synthesized in 48 % yield through the regio/stereoselective glycosylation between the LacNPhth polyol acceptor and a sialyl phosphite donor. Starting from d-glucosamine hydrochloride, the target Neu5Ac-α-2,3-LacNPhth derivative was synthesized in a total yield of 18.5 % over only 10 steps.