title: Divergent synthesis of L-sugars and L-iminosugars from D-sugars.
abstract: An efficient divergent synthesis of L-sugars and L-iminosugars from D-sugars is described. The important intermediate, delta-hydroxyalkoxamate, prepared from D-glucono-/galactono-1,5-lactone, was cyclized under Mitsunobu conditions to give the O-cyclized oxime compound and the N-cyclized lactam compound as mixtures. A more detailed investigation revealed that the appropriate protecting groups and solvents controlled the specificity for the O-/N-cyclization of the delta-hydroxyalkoxamate. Suitable protection at the 6-position of delta-hydroxyalkoxamate, derived from D-glucono-1,5-lactone, afforded the corresponding O-alkylation product alone. Thus we succeeded in applying this to the total synthesis of L-iduronic acid. In contrast, with both TBDMS as the protecting group and RCN as the solvent the efficient conversion of D-glucono/galactono-1,5-lactone into the corresponding L-iminosugars (L-idonolactam and L-altronolactam) was achieved.
authors.affiliation: School of Pharmaceutical Sciences, Teikyo University, Sagamiko, Sagamihara, Kanagawa, 199-0195, Japan.
authors.forename: Hideyo
authors.initials: H
authors.lastname: Takahashi
authors.forename: Tomomi
authors.initials: T
authors.lastname: Shida
authors.forename: Yuko
authors.initials: Y
authors.lastname: Hitomi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Iwai
authors.forename: Namisa
authors.initials: N
authors.lastname: Miyama
authors.forename: Kazusa
authors.initials: K
authors.lastname: Nishiyama
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sawada
authors.forename: Shiro
authors.initials: S
authors.lastname: Ikegami
mesh_terms: D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D007067:Iduronic Acid / Q000138:chemical synthesis*; D050111:Imino Sugars / Q000138:chemical synthesis*; D007783:Lactones / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013343:Styrenes / Q000737:chemistry
chemical_list: C506477:4-(tert-butyldimethylsiloxy)styrene; D002241:Carbohydrates; D050111:Imino Sugars; D007783:Lactones; D012833:Siloxanes; D013343:Styrenes; D007067:Iduronic Acid