α-D,L-Sorbose

Abstract

The racemic title compound, C 6 H 12 O 6 , consisting of C-4 epimers of psicose, was crystallized from an aqueous solution of an equimolar mixture of D- and L-sorboses. It was confirmed that D-sorbose (or L-sorbose) formed α-pyranose with a 4 C 1 (or 1 C 4 ) conformation where the anomer position was designated as carbon-1. The asymmetric unit comprises two crystallographically independent molecules. In the crystal, molecules are linked by O—H...O hydrogen bonds, forming a three-dimensional framework. The unit-cell volume of the title racemic α-D,L-sorbose is 1450.86 (6) Å 3 ( Z = 8), which is about 41 Å 3 smaller than that of twice the amount of chiral α-L-sorbose [ V = 745.942 Å 3 ( Z = 4)].