Potassium (1R,4R,5S,8S)-4,5,8-trihy-droxy-3-oxo-2,6-dioxabicyclo-[3.3.0]octane-4-sulfonate dihydrate.

ABSTRACT: The title salt, K(+)·C6H7O9S(-)·2H2O, formed by reaction of dehydro-l-ascorbic acid with potassium hydrogen sulfite in water, crystallizes as colourless plates. The potassium ion is coordinated by eight O atoms arising from hy-droxy or sulfonate groups. The sulfonate group is bonded to the C atom neighbouring that of the lactone carbonyl group. As is commonly observed in crystalline l-ascorbic acid derivatives, the O atom of the primary hy-droxy group is linked to the second C atom from the lactone C atom, forming a hemi-acetal function, thereby creating a bicyclic system of two fused five-membered rings, both of which have envelope conformations with one of the shared C atoms as the flap. Addition of the sulfur nucleophile occurs from the less hindered face. One of the two independent lat

SUBMITTER: Haines AH 

PROVIDER: S-EPMC3588254 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature