Allitol 2,6-dideoxy

On treatment with concentrated halogen acids, certain hexitols yield 1,6-dideoxy-l,6-dihalo compounds. The structure of the compound so obtained from galactitol, first reported by Bouchardat,404 was later verified by synthesis.405 Allitol is transformed406 into 1,4-anhydro-6-chloro-6-deoxy-DL-allitol and l,4-anhydro-5,6-dichloro-5,6-dideoxy-DL-talitol on treatment with fuming hydrochloric acid at 100°. 

When the dibromodideoxy-o-mannono-1,4-lactone (2) (Scheme 7) was treated with aqueous ammonia the 3,6-dideoxy-3,6-imino-D-allonamide (22) was formed as the only product [20]. Conversion to the ethyl ester and subsequent reduction of the ester with sodium borohydride transformed 22 into the known l,4-dideoxy-l,4-imino-L-allitol (23) [20]. 

Investigation of the inhibitory effects on glycosidases has been carried out for the hydroxylated pyrrolidines [65] and piperidines [73]. Among the pyrrolidines prepared only the l,4-dideoxy-l,4-imino-L-allitol (23) (Scheme 7) and its C-5 isomer showed any remarkable effects. They inhibited lysosomal a-manno-sidase rather than the processing a-mannosidases I and II [65], and their specificity is in accord with the structural requirements of azafuranose analogues of mannose for inhibiting mammalian a-o-mannosidases [80]. 

Substitution was also the major reaction in the deamination of l-amino-2,6-anhydro-l-deoxy-D-allitol 67and l-amino-2,6-anhydro-l,7-dideoxy-L-g(i/cero-L-ga(acfo-heptitol.168 The rearrangement product, a l,6-dideoxy-2-heptulose, was also isolated from the latter amine, the ratio of substitution to rearrangement being 1.6 1. 

One of the most efficient methods for the generation of 2,5-dideoxy-2,5-iminogalactitol 16 relies on the fuculose-1-phosphate aldolase-catalyzed aldol condensation of 2-azido-3-hydroxypropanal with dihydroxyacetone monophosphate (Scheme 13.17). The same method, applied to (2/ )-2-azidopropanal R)-V7 and to (25 )-2-azido-propanal (5 )-17, allows for the preparation of 2,5,6-trideoxy-2,5-imino-D-allitol 18 and 2,5,6-trideoxy-2,5-imino-L-talitol 19, respectively [22]. 

Acetamido-l,5-anhydro-3,4-di-0-benzyl-2-deoxy-D-mannitol, A-141 2-Acetamido-l,5-anhydro-3,4-di-0-benzyl-2,6-dideoxy-D-mannitol, A-149 2-Acetamido-l,5-anhydro-2,6-dideoxy-D-mannitol, A-149 l-Acetamido-2,5-anhydro-3,4,6-tri-0-benzoyl- 1-deoxy-D-allitol, A-122... 

Anhydro-1,6-dideoxy-1 -dimethylamino-D-gulitol, A-148 2-Benzamido-2-deoxy-D-allitol, A-155... 

Benzamido-1,3,4,5,6-penta- O -benzoyl-D-allitol, A-155 Benzyl 2,4-diamino-2,4-dideoxy-a-D-galactopyranoside, D-422 l-Deoxy-l-(methylamino)glucitol, 9CI, 8CI, A-214 l-Deoxy-l-[methyl(l-oxodecyl)amino]-D-glucitol, 9CI, A-214... 

Dibromo-2,6-dideoj -D-altrono-l,4-lactone can be converted into l-amino-3,6-anhydro-1 deoxy-D-allitol by reaction with sodium borol dride followed by aqueous ammonia. The same starting dibromide, on treatment with potasaum fluoride them aqueous ammonia, affords 3,6-dideoxy-3,6-imino-D-gluconic acid which can be reduced to l,4-dideoxy-l,4-iniuKM guIitol via the... 

A preparation of l,5-dideoxy-l,S-imino-D-allitol from A protected deoxynqjirimycin v ch involves a microbial redox reaction at C-3 has been described, and the glycosidase inhibitory properties of the product were determined together with those of other imino-alditols isolated from the leaves of Mens alba (see also ref 40 above). ... 

Anhvdro-Alditols. - The synthesis of a whole range of 1,5- and 1,4-anhydro-alditols and their inhibitory effects against glycosidases have been reported. The preparation of 2,5-anhydro-3-deoxy-D-araWno-hexitol by hydrogenation of 2,5 3,4-dianhydro-D-allitol over Pearlman s catalyst has been described. The selective chlorination of pentitols to afford l,5-dichloro-l,5-dideoxy derivatives as well as mono- and di-chloro-l,4-anhydro derivatives has been reported. ... 

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