Heptuloses derivatives

Phenylalanine- and Tyrosine-Derived Alkaloids. Carbohydrate metaboHsm leads via a seven-carbon sugar, ie, a heptulose, derivative to shikimic acid [138-59-0] (57), C H qO, which leads in turn to prephenic acid [126-49-8] (58), (43). 

Synthesis from aldonolactones The synthesis of p-homonojirimycin (2) from tetra-(9-benzyl-D-glucono-1,5-lactone (56) (Scheme 8) was achieved by treatment of the latter with (methoxymethoxy)methyl lithium to give the a-D-gluco-heptulose derivative 57, which underwent reduction with LiAlITj to produce a mixture of heptitols 58 (1 1 ratio). Oxidation of 58 using Swern oxidation (DMSO-TFAA) gave the heptodiulose 59. Compound 59 was immediately submitted to reductive amination using ammonium formate in the presence of sodium cyanoborohydride to produce 60 in 50% yield from 58. Removal... 

As is to be expected, activity in the field of acidic derivatives has remained high. Synthesis has been reported of benzyl 3-0-/3-D-glucuronosyl-/3-D-galactopyanoside and its 4-, 6-sulfates and 4,6-disulfate,and the L-serine linked amide derivative (109) has also been described. The corresponding heptulose derivative was condensed with various alcohols using pyridinium tosylate as catalyst to give disaccharides, and the liberated C-1 primary alcohol groups were oxidized to afford o-KDO compounds such as (110). ... 

LaForge and Hudson194 prepared an osone from the phenylosazone obtained from sedoheptulose (D-aZ(ro-heptulose). The osone reduced Fehling solution strongly, formed the original osazone with phenylhydrazine, and gave a crystalline derivative with o-phenylenediamine. 

Phase 3. Formation activation and modification of a putative NDP-heptose. We suggest that the heptose moiety is derived from erfo-heptulose-7-phos-phate, which is the universal source for heptoses in all organisms having a functional pentosephosphate cycle. Also, for C-7 cyclitols (e.g., valien-amine) or for secondary metabolic sugar units with longer C chains, such as octoses (e.g., lincosamine, or the octose unit in APR, see Section 2.2.4.2), this seems to be the preferred precursor in actinomycete pathways. ... 

This enzymically prepared product was, therefore, tested with bacterial extracts. Almost quantitative conversion to shikimate took place. Furthermore, D-olheptulose diphosphate labeled in carbon atoms 4,5,6, and 7 with C, prepared from uniformly labeled D-oZiro-heptulose 7-phosphate and unlabeled n-fructose diphosphate (see Fig. 3), was converted to shikimate labeled exclusively in carbon atoms 3,4,5, and 6. It is clear, however, that a cyclization of the intact carbon-chain of D-aZtriose phosphate isomerase, carbon atoms 1,2, and 3 of the heptulose diphosphate would be derived from G-(l,6), G-(2,5), and G-(3,4), respectively. Carbon atoms 7,1, and 2 of shikimate, as discussed previously (see Fig. 1), are derived from the reverse sequence, namely, G-(3,4), G-(2,5), and G-(l,6). Apparently, carbon atoms 1,2, and 3 of the heptulose diphosphate become detached, and their order is reversed, before their incorporation into shikimic acid. 

Reaction of l-bromo-l-deoxy-o-ga/acto-heptulose (151) with the pyra-zole derivative 152 in the presence of sodium methoxide gave the C-nucleoside 155 (86PHA548) (Scheme 46). 

This method for the synthesis of higher-carbon ketoses is based on the reaction of diazomethane with an acid chloride to give a diazomethyl ketone which, on hydrolysis (or acetolysis), furnishes a hydroxy (or acetoxy) methyl ketone. The reaction was first applied in the sugar field in 1938 and has since been widely used in the synthesis of ketoses by Wolfrom and coworkers. As developed by Wolfrom, the synthesis uses fully acety-lated derivatives in the following stages aldose — acetylated aldonic acid acetylated aldonyl chloride acetylated diazomethyl ketose — acetylated ketose — ketose. The method is illustrated in the synthesis of D-galacto-heptulose (10). ... 

J. W. Pratt and N. K. Richtmyer, D-glycero-D-allo-Ueptose, L-a/fo-heptose, D-ta/o-heptulose and related substances derived from the addition of cyanide to D-allose, J. Am. Chem. Soc., 11 (1955) 6326-6328. 

Alkylation of 2-deoxy-3,4 5,6-di-0-isopropylidene-D-crfli>mo-hexose diethyl dithioacetal at C-1 with butyl lithium-methyl iodide afforded the corresponding derivative of 1, S-dideoxy-D-craftwo-heptulose. ... 

Alkylamino-l-deoxy-D-fructoses reacted with potassium isocyanate in the presence of hydrochloric acid to give imidazole derivatives [e.g. (235)], while 1-amino-1-deoxy-D-gi/uco-heptulose gave the 4-[(polyhydroxy)a(kyl]pyrrole (236)... 

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