Trideoxyhexoses

Uridine 5 -(2-acetamido-2-deoxy-a-n-gIucopyranosyluronic acid pyrophosphate) (36) was isolated from extracts of Achromobacter georgiopolitanum14Sa and Micrococcus lysodeikticus.149b The ester of uridine 5 -pyrophosphate with an unusual amino sugar, namely, a 2-acetamido-2,4,6-trideoxyhexose of unknown configuration, has... 

Examples for the use of acetals such as 3, of 3-nitropropanal (1), and of 3-nitropropanol (2) or its O-protected derivatives are given in the references.22-24 A recent, notable application from this group is a short, high-yield synthesis of l-acosamine,25 the arabino isomer of 3-amino-2,3,6-trideoxyhexoses that form part of many antitumor aminoglycoside antibiotics 26... 

A similar reaction sequence without the last epimerization would yield D-abequose. CDP-D-tyvelose arises by C-2 epimerization of CDP-D-paratose.65a Other unusual sugars66-68 are formed from intermediates in Eq. 20-11. One is a 3-amino-3,4,6-trideoxyhexose in which the amino group has been provided by transamination67 (see also Box 20-B). 

A 2,3,6-trideoxyhexose, namely, rhodinose (63), was shown to be the neutral sugar component in the antibiotic rhodomycin. 24 The structure was established by periodate oxidation, with isolation of acetaldehyde and... 

It has been realized serendipitously that the initial product from aldolization of 122 to itself again serves as a suitable acceptor for sequential addition of a second donor molecule to give (3K,5K)-2,4,6-trideoxyhexose 127 in a 20% yield [372], By variation of the first acceptor in the form of substituted acetal-... 

Disregarding nonoxygen functional groups (amino, dimethylamino, and so on) only the 2,3,6-trideoxyhexoses were isolated from natural products. However, some of the isomeric trideoxyhexoses were chemically synthesized. Thus, the methyl a-glycosides of 3,4,6 - tr i de o xy - d - erj> f/ ro - he x o p y r a n o s e, 3,4,6-tri-deoxy-D-t/zreo-hexopyranose and 2,4,6-trideoxy-D-eryt/iro-hexopyranose were synthesized from methyl 4,6-dideoxy-a-D-xy/o-hexopyranoside via selective sub-... 

By analogy with the synthesis of /V-acetylneuraminic acid,63 di-A-acetyl derivatives of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acids could be obtained by condensation of 2,4-diacetamido-2,4,6-trideoxyhexoses with oxaloacetic acid under basic conditions. Four chiral centers in the C precursors, C-2 C-5, correspond to the centers C-5-C-8 in the target C9 products, and the fifth asymmetric center, C-4, is formed upon condensation. At present, derivatives of twelve 2,4-diamino-2,4,6-trideoxy-hexoses with the d-gluco, o-manno, L-allo, r>-galacto, D- and L-altro, D- and L-talo, D- and l-gulo, D- and L-ido configurations have been prepared by multistep chemical syntheses.11,17,18,64,65... 

Fig. 10. Chemical syntheses of 5,7-diacetamido-3,5,7,9-tetradeoxynon-2-ulosonic acids (34-42) from 2,4-diacetamido-2,4,6-trideoxyhexoses (30-33).11,17,18 (The reaction conditions 1.75 mol oxaloacetic acid, 0.4 mol Na2B407, pH 10.5, room temperature. The yields of the products are given in parentheses.)...

Sharon and Jeanloz86 describe the isolation of a crystalline 4-acetamido-2-amino-2,4,6-trideoxyhexose hydrochloride from Bacillus subtilis. 

From a polysaccharide of the Gram-positive organism BaciUus svbtilis, a related sugar has been isolated but not fully characterized it is a 4-acetamido-2-amino-2,4,6-trideoxyhexose. Another diamino sugar, a 2,6-diamino-2,6-dideoxyglucose, has been isolated from the antibiotic substance Neomycin. ... 

Diacetamido-2,4,6-trideoxyhexose DATDH Pili of Neisseria meningitidis and Neisseria gonorrhoeae... 

---