Structure of dihydroxyacetone phosphate dimethyl acetal, a stable dihydroxyacetone phosphate precursor, in the crystalline state

Crystal and molecular structures of four different salts of a dihydroxyacetone phosphate (DHAP) precursor, its dimethyl acetal [2,2-dimethoxy-1,3-propanediol phosphate, C5H13O7P, (MeO)2DHAP]: (cha)2[(MeO)2DHAP]·H2O (6a), (cha)[(MeO)2DHAP] (6b), Na2[(MeO)2DHAP]·5.75H2O (6c) and K2[(MeO)2DHAP]·H2O (6d), along with the cyclohexylammonium (cha) salt of its phenyl ester (cha)[(MeO)2DHAP(Ph)] (6e) are described. In the (MeO)2DHAP mono- and dianions, slightly different orientation of the phosphate group in relation to the acetal carbon atom is observed, with a delicate tendency of phosphate group to be located antiperiplanar in the monoanions and anticlinal in the dianions. The 2,2-dimethoxy-1,3-propandiol moiety, (MeO)2DHA, seems to be very rigid and its conformation is independent of phosphorylation, the ionization state of the inserted phosphate group and its additional substitution. The overall structures of the cyclohexylammonium (6a,b) and potassium salts (6d) have a double-layered architecture, while the sodium cation network in 6c forms the system of channels, which are filled up with the [(MeO)2DHAP]2− ions. The different architectures of 6c and 6d crystals result from the different ways in which the relevant dianions coordinate to sodium and potassium ions and affect also the hydrogen bonding system observed in 6c and 6d crystals.