Trideoxy sugars

D-Amicetose (173) is a constituent of the antibiotics of the antibiotics amice-tin,252 axenomycin,253 dutomycin,254 and polyketomycin.255 Amicetin is produced by Streptomyces spp. and the structure described in 1962.1,256 In polyketomycin (175) and dutomycin, the 3-C-methyl branched sugar L-axenose is a-(l - 4)-linked to amicetose,257 whereas in axenomycin, a macrolide antibiotic, the two deoxy sugars are p-linked in reverse order. Mild methanolysis (0.05 M HC1, rt) of axenomycine B gave among other products the glycoside 176.253 

Polyketomycin (175), produced by Streptomyces sp. MK277-AF1, has been described as a powerful antibiotic against multidrug resistant Staphylococcus aureus, and as antitumor agent.258 

Rhodinose (174) is the sugar linked in the antibiotic streptolydigin (177)1,259 and is a component of the oligosaccharides present in the rhodomycin family of anthracycline antibiotics. 1,260 

The preparation of benzyl 4- 9-acetyl-2,3,6-trideoxy-L-t/zra -hexopyranoside, a protected form of rhodinose, starting from L-rhamnose has also been described.271 

The chiral synthon, 2,2,5-trimethyl-L,3-dioxolane 4-carboxaldehyde, was also used for the preparation of rhodinose.273 

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Trideoxy sugars have also been prepared from aldono- 1,4-lactones. Thus, 2-0-benzoyl-3,5,6-trideoxy-a-D,L-t/ira>hexofuranose was obtained (202) from L-rhamnono- 1,4-lactone via the furanone 155. L-Rhamnono-1,5-lac-... 

In all cases, the sugar residues are attached to the 7-hydroxy group and this is the point of interest to carbohydrate chemistry. Until present, only the 3-amino-2,3,6-trideoxy sugars daunosamine (62) and rhodosamine (63) were found to be a-glycosi-dically linked to this position. The other saccharides 2-deoxy-L-fucose (64), L-cineru-... 

Several deoxy sugars, notably 2-deoxy-D-mY/ o-pentose (2-deoxy-D-ribose) the sugar component of DNA, 6-deoxy-L-mannose (L-rhamnose), 6-deoxy-L-galactose (L-fucose), 6-deoxy-D-glucose (quinovose), and their derivatives, occur very widely in natural products. Also relevant are dideoxy and trideoxy sugars, such as 3,6-dideoxyhexoses, components of the antigenic determinants bacterial... 

A. H. Haines, The synthesis of trideoxy sugars. A preparation of rhodinose (2,3,6-trideoxy-a-L-t/ireo-hexose) and methyl 2,3,6-trideoxy-a-L-eryr/u-o-hexopyranoside, Carbohydr. Res., 21 (1972) 99-109. 

Curtius reaction. - The C-3-branched 3-amino-2,3,6-trideoxy-sugar analogue 40 of daunosamine has been synthesized from the di-C-branched derivative 39, and converted to the bicyclic derivative 41 (Scheme 11). Preparation of an analogous derivative 42 from a known... 

Chapter 12(2,3,4,-trideoxy-sugars), Chapter 14 (3- and 2,3-branched-chain sugars), and Chapter 20 (nucleosides). References to 4, 5 -unsaturated nucleosides and to 5,6-unsaturated hexopyranosyl compounds appear in Chapters 20 and 18, respectively. 

The L-arabinose derived enal (33) (c/. Vol. 24, p. 112) was a common starting material in syntheses of the trideoxy-sugar L-rhodinose (35) and the epimeric dideoxy-sugars L-diginose (36) and L-sarmentose (37) (Scheme 5). The epimeric intermediates (34) were separated and independendy converted into (36) and (37). The D-enantiomers of (36) and (37) were similarly prepared from D-arabinose. Methyl a,p-D-ribofuranoside was converted to l-O-acetyl-5-0-benzoyl-2,3-dideoxy-a,p-D-eo A c-pcntofuranose by radical deoxygenation (BujSnH) of a 2,3-0-... 

Butte, J. C., and J. W. Corcoran The biogenesis of desosamine, an amino-trideoxy-sugar in erythromycin. Federation Proc. 21, 89 (1962). 

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