Crystal structure of β-d,l-psicose

Tomohiko Ishii; Genta Sakane; Akihide Yoshihara; Kazuhiro Fukada; Tatsuya Senoo

doi:10.1107/S2056989015006623

Crystal structure of β-d,l-psicose

Acta Crystallogr E Crystallogr Commun. 2015 Apr 9;71(Pt 5):o289-90. doi: 10.1107/S2056989015006623. eCollection 2015 May 1.

Authors

Tomohiko Ishii¹, Genta Sakane², Akihide Yoshihara³, Kazuhiro Fukada⁴, Tatsuya Senoo¹

Affiliations

¹ Department of Advanced Materials Science, Faculty of Engineering, Kagawa University, 2217-20 Hayashi-cho, Takamatsu, Kagawa 761-0396, Japan.
² Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama 700-0005, Japan.
³ Rare Sugar Research Center, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Kagawa 761-0795, Japan.
⁴ Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Kagawa 761-0795, Japan.

Abstract

The title compound, C6H12O6, a C-3 position epimer of fructose, was crystallized from an aqueous solution of equimolar mixture of d- and l-psicose (1,3,4,5,6-penta-hydroxy-hexan-2-one, ribo-2-hexulose, allulose), and it was confirmed that d-psicose (or l-psicose) formed β-pyran-ose with a (2) C 5 (or (5) C 2) conformation. In the crystal, an O-H⋯O hydrogen bond between the hy-droxy groups at the C-3 and C-2 positions connects homochiral mol-ecules into a column along the b axis. The columns are linked by other O-H⋯O hydrogen bonds between d- and l-psicose mol-ecules, forming a three-dimensional network. An intra-molecular O-H⋯O hydrogen bond is also observed. The cell volume of racemic β-d,l-psicose [763.21 (6) Å(3)] is almost the same as that of chiral β-d-psicose [753.06 Å(3)].

Keywords: crystal structure; hydrogen bonding; racemic compound; rare sugar.