title: Chemical Synthesis of a Complex-Type N-Glycan Containing a Core Fucose.
abstract: A chemical synthesis of a core fucose containing N-glycan was achieved. Asparagine was introduced at an early stage of the synthesis, and the sugar chain was convergently elongated. As for the fragment synthesis, we reinvestigated α-sialylation, β-mannosylation, and N-glycosylation to reveal that precise temperature control was essential for these glycosylations. Intermolecular hydrogen bonds involving acetamide groups were found to reduce the reactivity in glycosylations: the protection of NHAc as NAc2dramatically improved the reactivity. The dodecasaccharide-asparagine framework was constructed via the (4 + 4) glycosylation and the (4 + 8) glycosylation using the tetrasaccharide donor and the tetrasaccharide-asparagine acceptor. An ether-type solvent enhanced the yields of these key glycosylations between large substrates. After the whole deprotection of the dodecasaccharide, the target N-glycan was obtained.
authors: Department of Chemistry, Graduate School of Science, Osaka University , Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.
authors: Masahiro
authors: M
authors: Nagasaki
authors: Department of Chemistry, Graduate School of Science, Osaka University , Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.
authors: Yoshiyuki
authors: Y
authors: Manabe
authors: Department of Chemistry, Graduate School of Science, Osaka University , Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.
authors: Naoya
authors: N
authors: Minamoto
authors: Department of Chemistry, Graduate School of Science, Osaka University , Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.|Biofunctional Synthetic Chemistry Laboratory, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198, Japan.
authors: Katsunori
authors: K
authors: Tanaka
authors: Department of Chemical Science, University of Naples Federico II , Via Cinthia 4, 80126 Napoli, Italy.
authors: Alba
authors: A
authors: Silipo
authors: Department of Chemistry, Graduate School of Science, Osaka University , Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.|Department of Chemical Science, University of Naples Federico II , Via Cinthia 4, 80126 Napoli, Italy.
authors: Antonio
authors: A
authors: Molinaro
authors: Department of Chemistry, Graduate School of Science, Osaka University , Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.
authors: Koichi
authors: K
authors: Fukase