Conversion of 2,3,5,6-tetra-O-benzyl-~-galactofuranose (1 9) into its oxime and subsequent treatment with methanesulphonyl chloride gave 2,3,5,6-tetra-O-benzyl-4-O-rnethylsulphonyl-~galactonitrile (21 ). Reductive cyclization by sodium borohydride/cobalt( 11) chloride, followed by hydrogenolysis under acidic conditions yielded 1,4-dideoxy-l,4-imino-~-glucitol hydrochloride (11). A similar reaction sequence was used to convert 2,3,5-tri-O-benzyl L-arabinofuranose (23) via the nitrile (25) into 1,4-dideoxy-I ,4-imino-~-xylitol hydrochloride (1 2), and the corresponding Darabinose derivative (27) gave 1,4-dideoxy-I ,4-imino-~-xylitol hydrochloride (1 3), using the same chemistry. Treatment of 2,3: 5,6-di-~-isopropylidene-~-~-gu~ofuranose (31 ) with hydroxylamine and then methanesulphonyl chloride in pyridine gave 4-0methylsul phony1 -2,3 : 5,6-di -0isopropylidene-Dgulononitrile (32), which was converted by treatment with lithium aluminium hydride and subsequent acid hydrolysis into 1,4-dideoxy-l,4-imino-~-allitol hydrochloride (1 4); similar chemistry in the enantiomeric series gave the L-allitol derivative (1 5). An analogous reaction sequence was used to convert 2,3: 5,6-di-O-isopropylidene-~-~-rnannofuranose into 4 -0methylsulphonyl-2,3: 5,6-di-O-isopropyIidene D-mannononitrile (38) and thence into 1,4-dideoxy-1,4-imino-~-talitol hydrochloride (1 6); L-mannonolactone was converted via 2,3 : 5,6-di-0isopropylidene-a-L-mannofuranose (41 ) into 1,4-dideoxy-I ,4-imino-~-talitol hydrochloride (1 7). 2,3: 5,6-Di-O-isopropylidene-~-~-allofuranose (45) was converted via its oxime (46) into 4 -0methylsulphonyl-2,3:5,6-di-0-isopropylidene-~-allononitrile (47), which on reductive cyclization with lithium aluminium hydride, and subsequent acid hydrolysis, gave 1,4-dideoxy-l,4-imino-~gulitol hydrochloride (1 8).
