Hexose, 2,6-dideoxy-3-0-methyl

Some of the rare sugars that have been prepared by way of chloro-deoxy derivatives are 4,6-dideoxy-3-0-methyl-D-xyZo-hexose (D-chal-cose), 3,6-dideoxy-D-n foo-hexose (paratose), 3,6-dideoxy-D-arafcmo-hexose (tyvelose), methyl 2,3-dideoxy-/3-D-glr/cero-hex-2-enopyrano-sid-4-ulose, and certain aminodeoxy sugars. 

There has been substantial activity in the synthesis of 3-amino-2,3,6-trideoxy-hexoses and their di-A-methyl derivatives as a result of their wide occurrence in antibiotics. In a paper of substantial proportions, Bartner et alP have synthesized by standard reactions all four possible methyl 2,3,6-dideoxy-3-dimethylamino-a-D-hexopyranosides (and some /3-anomers) as well as the corresponding L-ribo isomer (L-megosaminide). Syntheses have been reported for D-ristosamine (3-amino-2,3,6-trideoxy-D-rz7 o-hexose) from methyl 2-deoxy-D-amfcmo-hexo-pyranoside and of the isomeric 3-amino-2,3,6-trideoxy-L-Jcy/o-hexose (1) from methyl 2,6-dideoxy-L- mZ>mo-hexopyranoside, using standard sequences involving azidej displacement of sulphonate esters for introducing the nitrogen. 

Compounds (35) and (36) were prepared using 5-deoxy-l,2-0-isopropylidene-D-xyto-hexose and methyl 4,6-dideoxy-a-D-xyZo-hexopyranoside, respectively, and, together with the Wittig reagent (37), were built into the macrocyclic lactone antibiotic (38). The source of each carbon atom in the product is indicated. ... 

Product 15 was eventually transformed into methyl 4,6-dideoxy-a-D-xylo-hexopyranoside by reductive desulfurization. A related reaction is the formation (41) of the 4-thiocyanato derivative 17 in 47% yield from 16 (140°C., 22 hours in N,N-dimethylformamide). This has been suggested as a good route to 4-deoxy-D-xt/Zo-hexoses compared with the available methods (43). 

Dideoxy-3-[3-hydroxy-2-(hydroxymethyl)propyl]-4-C-methyl-L-mannose (not the alternative /Ztrco-hexose)... 

The carbon atoms of the parent chain are numbered according to 2-Carb-2.2.1. If a unique numbering is required for the branch(es) (e.g. for X-ray orNMR work), the carbon atoms may be given the locant of the appropriate branch point, with the internal branch locant as superscript, e.g. 42 for position 2 of the branch at position 4 of the main chain. This style of branch numbering is not to be used for naming purposes e.g. the side-chain-methylated derivative of compound 5 is named 4,6-dideoxy-3-C-[(I )-1 -methoxyethyl]-D-n7w-hexose, and not as a s -O-methyl derivative. 

Cladinose 2,6-Dideoxy-3-C-methyl-3-Omethyl- L-ribo-hexose... 

Oleandrose Panose 2,6-Dideoxy-3-0-methyl-L-arab/no-hexose a-D-Glucopyranosyl-(1 ->6)-a-D-glucopyranosyl-(1- 4)-D-glucose... 

Sarmentose Sedoheptulose Sedoheptulosan Solatriose 2.6- Dideoxy-3-0-methyl-D-xy/o-hexose D-a/froHept-2-ulose 2.7- Anhydro P-D-a/fro-hept-2-ulopyranose a-L-Rhamnopyranosyl-(1 ->2)-[P-D-glucopyranosyl-(1->3)]-D-galactose... 

P2j Z = 2 D = 1.17 R = 0.080 for 3,888 intensities. This is aconfigu-rational analysis of the macrolide antibiotic 23672RP from Streptomyces chryeus. All three sugar residues are pyranoid the conformation of the a-ketose is CX, with Q = 56 pm, 0 = 9° that of the / -D-mycinose (6-deoxy-2,3-di-0-methyl-D-allose) is 4Clt with Q = 59 pm, 0 = 6° and that of the / -L-mycarose (2,6-dideoxy-3-C-methyl-L-riho-hexose) is 1C4, with Q = 53 pm, 0= 177°. The O-5-C-l-O-l-C glycosidic torsion-angles are —71, —87, —83°. The atomic coordinates reported in the paper refer to the opposite enantiomer. 

An important step in the synthesis of paratose (3,6-dideoxy-n-rtfoo-hexose) involved the conversion of methyl 3-chloro-3-deoxy-/8-D-allopyranoside into methyl 3,6-dichloro-3,6-dideoxy-/8-D-allo-pyranoside in 33% yield.359... 

Diisobutylaluminum hydride was also employed (153) for the reduction of 2,6-dideoxy-3-C-methyl-D-arabmo-hexono-1,4-lactone (121) to an antibiotic component, the branched-chain sugar evermicose (2,6-dideoxy-3-C-methyl-D-nrabmo-hexose, 122). The L-enantiomer of 122 (olivomycose, 125a), L-amicetose 125b, and 2,6-dideoxy-3-C-methyl-L-n Zw-hexose (l-... 

From his time at the Squibb research laboratories, he was interested in the chemistry of antibiotics, and in this area, he elucidated the partial structure of curamycin, an antibiotic produced by Streptomyces curacoi. From curamycin, he isolated and characterized the new natural sugar derivatives D-curacose (4-O-methyl-D-fucose), curacin [4-0-(dichlo-roisoeveminyl)-2,6-dideoxy-D-araW/io-hexose], and curamycose (2,6-di-O-methyl-D-mannose). 

Branched-chain sugars are found in nature, eg, dadinose, ie, 2,6-dideoxy-3-C-methyl-3-O-methyl-L-/7 < hexose [57584-5-0], a component of erythromycin. 

Dideoxy-3-C-methyl-4-(methylamino)-D-altrose (22) 3-Amino-2,3,6-trideoxy-3-C-methyl-L-/j/xo-hexose (23)... 

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