Cyclic dimerization of 1,2-unsaturated maltotriose derivatives with iodinium addition; one-pot preparation of a fully methylated 2 A ,2 D -dideoxy-2 A ,2 D -diiodocyclohexasaccharide
作者:Nobuo Sakairi、Hiroyoshi Kuzuhara
DOI:10.1039/c39930001874
日期:——
Iodonium ion treatment of 1,2-unsaturated octa-O-methylmaltotriose having a sole hydroxy group at the 4″-position results in dimerization of the trisaccharide derivative with simultaneous cyclization, giving a fullymethylated cyclohexasaccharide consisting of four α-D-glucopyranosyl residues and two 2-deoxy-2-iodo-α-D-mannopyranosyl residues.
Chemical Synthesis of Cyclodextrins by Using Intramolecular Glycosylation
作者:Masahiro Wakao、Koichi Fukase、Shoichi Kusumoto
DOI:10.1021/jo025887r
日期:2002.11.1
An efficient synthesis of cyclodextrins (CDs) by using the intramolecular glycosylation is demonstrated. alpha-CD, an alpha(1-->4)linked hexaglucoside, was prepared via a block condensation of three maltose units. A modified key maltose intermediate as a precursor to both glycosyl donor and acceptor components was prepared in 6 steps starting from maltose. All the glycosylation for chain elongation and cyclization of saccharides was carried out after tethering the donor to the acceptor by the phthaloyl bridge to give the desired saccharides in good yields with complete alpha-selectivity. delta-CD composed of 9 glucose units was synthesized by the same manner from three maltotriose units.