3-amino-3-cyano-3-deoxy sugar

Synthesis of 3-amino-3-cyano-3-deoxy sugars via the Hofmann rearrange-... 

A sugar derivative related to the purine nucleosides, namely methyl 5-(adenin-l-yl)-5-deoxy-2,3-0-isopropylidene-j8-D-ribofurano-side, is formed by the reaction of methyl 5-amino-5-deoxy-2,3-0-iso-propylidene-jS-D-ribofuranoside with l-benzyl-5-cyano-4[(ethoxy-methylene)amino]imidazole, followed by removal of the benzyl group. On fusion, this compound rearranges to methyl 5-deoxy-2,3-0-isopropylidene-5-[(purin-6-yl)amino]-/8-D-ribofuranoside, which can also be obtained from the reaction of methyl 5-amino-5-deoxy-2,3-0-isopropylidene-/8-D-ribofuranoside with 6-chloro-9-(tetrahydropyran-2-yl)purine. In the same manner, methyl 5-amino-5-deoxy-2,3-di-0-p-tolylsulfonyl-/3-D-ribofuranoside reacts with 6-chloro-9-(tetrahydro-pyran-2-yl)purine to give methyl 5-deoxy-5-[9-(tetrahydropyran-2-yl)-purin-6-yl]amino-2,3-di-0-p-tolylsulfonyl-j8-D-ribofuranoside. With liquid ammonia, 5 -0-p-tolylsulfonyladenosine gives 5 -amino-5 -deoxyadenosine. On heating in p-dioxane, ring closure to 3,5 -an-hydroadenosine is observed. ... 

Reduction of the 3-C-cyano 3-sulphonate derivative (118) with lithium aluminium hydride furnished the branched-chain sugar (119) and the spiro-epimine (120), which, on further reduction and 7V-acetylation, gave 3-acetamido-3-deoxy-l,2 5,6-di-(7-isopropylidene-3-C-methyl-a-D-glucofuranose. The latter branched-chain amino-sugar was also converted into related o-xylofuranose derivatives by a conventional chain-shortening procedure, following removal of the 5,6-0-isopropylidene group. 

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