Equilibrium States of 3-Ketoses and Sedoheptulose-The Factor Favoring α-Furanose Formation of Coriose

Abstract

Furanose was found by the spectral methods to be preponderant in the equilibrated solutions of coriose and sedoheptulose, while pyranose was shown to be the main constituent in equilibrated DL-gluco-3-heptulose and D-ido-3-heptulose. These examples show stableness of five-membered ring having three hydroxyl groups vic and cis to each other, relative to six-membered ring having 1, 3-diaxial hydroxyl groups.