Hexose deoxy-dimethylamino

Hydride reduction of methyl 3-deoxy-3- dimethylamino)-2,4,6-tri-O-p-tolylsulfonyl-a-D-rtho-hexopyranoside in tetrahydrofuran gave the corresponding 6-deoxy sugar which, on hydrolysis, afforded 3,6-dideoxy-3-(dimethylamino)-j8-D-riho-hexose this was found to be identical witii mycaminose, a component of an antibiotic substance. Syntheses of 4,6-dideoxy-3-0-methyl-D-xyi o-hexose (chalcose) have been reported by the intermediate hydride reduction, in tetrahydrofuran, of 6-p-toluenesulfonates methyl 4-deoxy-6-0-p-tolylsulfonyl-a-D-xy/o-hexopyranoside afforded, by such treatment, the corresponding 6-deoxy glycoside, and methyl 4-deoxy-3-0-methyl-2,6-di-O-p-tolylsulfonyl-a-D-xi/Zo-hexopyranoside gave a mixture of five products, from which methyl a-D-chalcoside was isolated in 26% yield. 

According to Irvine and Hynd, the deamination of methyl 2-deoxy-2-(dimethylamino)-D-glucopyranoside with a hot solution of barium hydroxide provides methyl n-glucoside. The effect of conformation on the nitrous acid deamination of amino hexoses is further illustrated by the reaction of methyl 3-amino-4,6-0-benzylidene-3-deoxy-a-D-altropyrano-side (LXVII) which, on deamination with nitrous acid, provides a quantitative yield of methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannoside (LXVIII). The deamination of methyl 3-amino-3-deoxy-)8-D-altropy-ranoside, methyl epiglucosamine, gives a sirupy mixture. Similar treatment of methyl 2-amino-4,6-0-benzylidene-2-deoxy-a-D-altroside... 

Amosamine is, therefore, the second reported example of a naturally occurring 4-deoxy-4-(dimethylamino)hexose derivative [see structure (24)]. 

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. 

Dihydroxypentanoic acid AR,5R)-form, D-707 3-(Dimethylamino)-2,3,6-trideoxy-/yxo-hexose i.-form, D-727 Ethyl 3,6-anhydro-7-(2-benzoyl-2-deoxy-4,5-0-isopropylidene-D-a//o-... 

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