Facile ring transformation from gluconolactone to cyclitol derivative via spiro sugar ortho ester.
[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.
Ohtake
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H
School of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa, Japan.
Ikegami
S
S
D002241:Carbohydrates / Q000737:chemistry*; D004952:Esters; D005942:Gluconates / Q000737:chemistry*; D007783:Lactones; D015394:Molecular Structure
D002241:Carbohydrates; D004952:Esters; D005942:Gluconates; D007783:Lactones; C010730:beta-glucono-1,5-lactone