Short and efficient synthesis of a stock material of dihydroxyacetone phosphate from glycidol

Dihydroxyacetone phosphate, DHAP, in the crystalline state: monomeric and dimeric forms

It was shown that dihydroxyacetone phosphate may exist in both monomeric DHAP (C(3)H(7)O(6)P) and dimeric DHAP-dimer (C(6)H(14)O(12)P(2)) form. Monomeric DHAP was obtained in the form of four crystalline salts: CaCl(DHAP) x 2.9H(2)O (7a), Ca(2)Cl(3)(DHAP) x 5H(2)O (7b), CaCl(DHAP) x 2H(2)O (7c), and CaBr(DHAP) x 5H(2)O (7d) by crystallization from aqueous solutions containing DHAP acid and CaCl(2) or CaBr(2), or by direct crystallization from a solution containing DHAP precursor and CaCl(2). At least one of the salts is stable and may be stored in the crystalline state at room temperature for several months. The dimeric form was obtained by slow saturation of free DHAP syrup with ammonia at -18 degrees C and isolated in the form of its hydrated diammonium salt (NH(4))(2)(DHAP-dimer) x 4H(2)O (8). The synthesis of the compounds, their crystallization, and crystal structures determined by X-ray crystallography are described. In all 7a-d monomeric DHAP exists in the monoanionic form in an extended (in-plane) cisoid conformation, with both hydroxyl and ester oxygen atoms being synperiplanar to the carbonyl O atom. The crucial structural feature is the coordination manner, in which the terminal phosphate oxygen atoms act as chelating as well as bridging atoms for the calcium cations. Additionally, the DHAP monoanions chelate another Ca(2+) by the alpha-hydroxycarbonyl moiety, in a manner observed previously in dihydroxyacetone (DHA) calcium chloride complexes. In dimeric 8 the anion is a trans isomer with the dioxane ring in a chair conformation with the hydroxyl groups in axial positions and the phosphomethyl group in an equatorial position.

Characterization of enzymatic D-xylulose 5-phosphate synthesis

In this article we report on the characterization of the enzymatic synthesis of D-xylulose 5-phosphate using triosephosphate isomerase and transketolase. Two potential starting substrates are possible with this scheme. The data presented here allow a comparison of both routes for the synthesis, based on experimental information on reaction kinetics. Operational guidelines are proposed which should assist in the scale-up of such syntheses.

Chemical and enzymatic routes to dihydroxyacetone phosphate

Stereoselective carbon-carbon bond formation with aldolases has become an indispensable tool in preparative synthetic chemistry. In particular, the dihydroxyacetone phosphate (DHAP)-dependent aldolases are attractive because four different types are available that allow access to a complete set of diastereomers of vicinal diols from achiral aldehyde acceptors and the DHAP donor substrate. While the substrate specificity for the acceptor is rather relaxed, these enzymes show only very limited tolerance for substituting the donor. Therefore, access to DHAP is instrumental for the preparative exploitation of these enzymes, and several routes for its synthesis have become available. DHAP is unstable, so chemical synthetic routes have concentrated on producing a storable precursor that can easily be converted to DHAP immediately before its use. Enzymatic routes have concentrated on integrating the DHAP formation with upstream or downstream catalytic steps, leading to multi-enzyme arrangements with up to seven enzymes operating simultaneously. While the various chemical routes suffer from either low yields, complicated work-up, or toxic reagents or catalysts, the enzymatic routes suffer from complex product mixtures and the need to assemble multiple enzymes into one reaction scheme. Both types of routes will require further improvement to serve as a basis for a scalable route to DHAP.

Lewis Acid Mediated Regioselective Ring Opening of Benzylglycidol with Dibenzyl Phosphate: Short and Attractive Synthesis of Dihydroxyacetone Phosphate

A novel, mild, and efficient method was described to introduce a dibenzyl phosphate by ring opening of benzylglycidol mediated by Lewis acids. This methodology was used as a key step for synthesizing the dihydroxyacetone phosphate (DHAP) in only three steps with an overall yield of 74% from the commercially available racemic benzylglycidol.

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, C(5)H(13)O(7)P, (MeO)(2)DHAP]: (cha)(2)[(MeO)(2)DHAP].H(2)O (6a), (cha)[(MeO)(2)DHAP] (6b), Na(2)[(MeO)(2)DHAP].5.75H(2)O (6c) and K(2)[(MeO)(2)DHAP].H(2)O (6d), along with the cyclohexylammonium (cha) salt of its phenyl ester (cha)[(MeO)(2)DHAP(Ph)] (6e) are described. In the (MeO)(2)DHAP 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)(2)DHA, 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)(2)DHAP](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.