Diastereoisomerically Pure, (S)-O-1,2-O-isopropyli dene-(5-O-α-d-glucofuranosyl) t-butanesulfinate: Synthesis, Crystal Structure, Absolute Configuration and Reactivity

Abstract

The reaction of t-butylmagnesium chlorides with diastereomerically pure (R)-1,2-O-isopropylidene-3,5-O-sulfinyl-α-d-glucofuranose (R)-4 was found to be stopped at the stage of the corresponding, diastereoisomerically pure 1,2-O-isopropylidene-(5-O-α-d-glucofuranosyl) t-butanesulfinate (S)-10 for which the crystal structure and the (S)-absolute configuration was determined by X-ray crystallography. Comparison of the absolute configurations of the starting sulfite (R)-4, and t-butanesulfinate (S)-10 (which crystallizes in the orthorhombic system, space group P212121, with the single compound molecule present in the asymmetric unit), clearly indicates that the reaction of nucleophilic substitution at the stereogenic sulfur atom in the sulfite (R)-4 occurs with the full inversion of configuration via the trigonal bipyramidal sulfurane intermediate 4c in which both the entering and leaving groups are located in apical positions.

Absolute Configuration Determination of Sugar: A Review of the Different Methods

“…The most effective approach to producing glycosyl sulfoxides is the oxidation of glycosyl sulfides. The use of hydrogen peroxide to convert sulfides into sulfoxides has proven to be one of the most attractive methods [34]. The reaction of t-butylmagnesium chlorides with diastereomerically pure (R)-1,2-Oisopropylidene-3,5-O-sulfinyl-α-D-glucofuranose (R)-4 was found to be stopped at the stage of the corresponding, diastereoisomerically pure 1,2-Oisopropylidene-(5-O-α-D-glucofuranosyl) tbutanesulfinate (S)-10 for which the crystal structure and the (S)-absolute configuration was determined by X-ray crystallography [33].…”