The crystal structure of the title diacetone psicose, C12H 20O6, establishes the stereochemistry of the anomeric spiroacetal 1,2:3,4-di-O-isopropylidene-β-D-psicofuranose. The structure consists of columns of molecules linked by hydrogen bonds into chains [O⋯O 2.962 (2) Å] lying parallel to the a axis. © 2005 International Union of Crystallography Printed in Great Britain - all rights reserved.