title: Facile ring transformation from gluconolactone to cyclitol derivative via spiro sugar ortho ester.
abstract: [reaction: see text] A short step preparation of cyclitol derivative 8 which is a versatile synthon for the synthesis of valiolamine and its related compounds is described. Key steps in this preparation are a novel enol ether formation from spiro sugar ortho esters with AlMe3 and an intramolecular Aldol condensation of alkyl enol ethers catalyzed by ZnCl2 in THF-H2O. With these reactions, gluconolactone derivative 1 was efficiently converted into 8 in short steps.
authors.affiliation: School of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ohtake
authors.forename: S
authors.initials: S
authors.lastname: Ikegami
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D004952:Esters; D005942:Gluconates / Q000737:chemistry*; D007783:Lactones; D015394:Molecular Structure
chemical_list: D002241:Carbohydrates; D004952:Esters; D005942:Gluconates; D007783:Lactones; C010730:beta-glucono-1,5-lactone