Contemporary Syntheses of 2-Ketoheptoses and Derivatives

Hybrid Chemoenzymatic Synthesis of C7‐Sugars for Molecular Evidence of in vivo Shikimate Pathway Inhibition

“…Comparison of the relative activity of 7dGh (5) and 5,7ddGh (6), of � 0.3 (143.5 : 464.7, IC 50 ) and � 0.7 (85.5 : 118.3, IC 50 ), respectively, in relation to 7dSh (1) indicated that the opposite stereo chemistry at C-5 has an adverse impact on the inhibitory activity. Diametral spatial charge distribution or insufficient space within the active pocket (as for 7d5MSh, 4) could be responsible for the lower activity of 7dGh (5). In accordance with the good in vitro activity of 5,7ddGh (6), a decreased root length could be detected.…”

“…Two synthetic routes are common but mainly restricted to manno-and glucoheptulose syntheses: one is a rearrangement e. g., by the Lobry de Bruyn-Alberda van Ekenstein transformation, and the other includes chain elongation at C-1, e. g., by oxidation and subsequent Wittig reaction. [5,6] Our use of the enzyme transketolase simplifies the synthesis, based on the transfer of a C 2 -unit onto an C 5 -aldehyde in only one step from the modified C 5 -aldehyde to the C 7 -carbohydrate. However, the enzyme reaction is restricted by two essential prerequisites, namely the preferred (R)-configuration at C-2 of the C 5 -aldehyde and the (S)-configuration of the newly formed chiral center, leading to an (3S, 4R)-ketose.…”

“…[19] Figure 2. A) Structural comparison of DAHP, carbaphosphonates (C1, C4À C6), 7dSh (1) and C 7 -sugar analogues (2)(3)(4)(5)(6). Compared to 7dSh (1), all structural differences are highlighted in red.…”

Synthesis, Derivatization, and Structural Analysis of Phosphorylated Mono-, Di-, and Trifluorinated d-Gluco-heptuloses by Glucokinase: Tunable Phosphoglucomutase Inhibition

“…2 Recently, it was found that fluorinated heptulose analogues functioned as tools for the noninvasive imaging of GLUT2-expressing insulin-producing cells by 19 F magnetic resonance imaging ( 19 FMRI). 3 In order to evaluate their spectrum of potential biological activities, ketoheptose analogues have been accessed by either chemical 1,4 or enzymatic 5 methods, with fluorinated carbohydrates as prominent tools to study various biochemical processes including structural and mechanistic investigations, 6 radio-labeling, 7 lectin–carbohydrate interactions, 8 and carbohydrate lipophilicity. 9 Further functionalization of ketoheptoses will provide access to mechanistic probes such as C-glycosides or analogues of glucose 6-phosphate (G6P) or glucose 1-phosphate (G1P).…”

Synthesis of D-manno-heptulose via a cascade aldol/hemiketalization reaction

“…The known synthesis of D- manno -heptulose mainly rely on the use of rearrangements and chain elongation reactions [ 17 ]. Rearrangement reactions such as the Lobry de Bruyn rearrangement and the Bilik rearrangement employ unprotected aldoses as substrates, usually yielding an equilibrium mixture of aldoses and ketoses [ 18 – 19 ].…”