Stereochemistry of carbohydrate derivatives. Part III. Crystal and molecular structure of (2R,4S,6S)-2-hydroxymethyl-6-methoxy-1,4-oxathian S-oxide

Abstract

X-Ray crystallographic analysis has established that the major sulphoxide obtained by periodate oxidation of (2R,6S)-2-hydroxymethyl-6-methoxy-1,4-oxathian (I) is (2R,4S,6S)-2-hydroxymethyl-6-methoxy-1,4-oxathian S-oxide (II). The 1,4-oxathian ring has a chair conformation, which is somewhat distorted from the ideal shape by the presence of the hetero-atoms. Crystals of sulphoxide (II) are orthorhombic, space group P2₁2₁2₁, with Z= 4, a= 7·99, b= 11·55, and c= 8·88 Å. The structure was established by Fourier and least-squares methods and the final value of R is 10·5% for 961 structure amplitudes.