578007-61-1Relevant articles and documents
Unusual α-glycosylation with galactosyl donors with a C2 ester capable of neighboring group participation
Chen, Langqiu,Kong, Fanzuo
, p. 3691 - 3695 (2003)
Glycosylation of 4-methoxyphenyl 2,3,6-tri-O-benzoyl-β-D-glucopyranoside (2) with isopropyl 3-O-allyl-2,4,6-tri-O-benzoyl- (9) or 6-O-allyl-2,3,4-tri-O-benzoyl-1-thio-β-D-galactopyranoside (7) as the donor, afforded an α- and β-linked mixture, whereas with isopropyl 3-O-chloroacetyl-2-O-benzoyl-4,6-O-benzylidene- (13) and isopropyl 3-O-allyl-2-O-benzoyl-4,6-O-benzylidene-1-thio-β-D-galactopyranoside (15) as the donor, glycosylation of 2 gave α-linked products only, indicating that 4,6-O-benzylidenation led to α-stereoselectivity in spite of the C2 ester capable of neighboring group participation. Using 15 as the donor, glycosylation of mannose derivatives with 2- or 3-OH's, glucose with 2- or 3-OH's, galactose with 2-, or 3-, or 4-OH's, glucosamine and glucuronic acid with a 4-OH, and a lactose derivative with a 4-OH, also furnished α-linked products. However, when using 15 as the donor, glycosylation of aglycon alcohol or sugars with 6-OH's yielded normal β-linked products.
A concise and practical synthesis of antigenic globotriose, α-d-Gal-(1→4)-β-d-Gal-(1→4)-β-d-Glc
Chen, Langqiu,Zhao, Xing-E.,Lai, Duan,Song, Zhiwei,Kong, Fanzuo
, p. 1174 - 1180 (2007/10/03)
A concise and practical synthesis of the antigenic globotriose, α-d-Gal-(1→4)-β-d-Gal-(1→4)-β-d-Glc (13), was achieved by coupling of a monosaccharide donor, 3-O-allyl-2-O-benzoyl-4,6-O-benzylidene-α-d-galactopyranosyl trichloroacetimidate (4) with a disa