Isoxazolines, from disaccharides

Enones 167 derived from disaccharides melibial and gentobial reacted with 2equiv of hydroxylamine to afford isoxazolines 168 as an inseparable epimeric mixture in 80-83% yield. By treatment with />-toluenesulfonic acid, compounds 168 underwent dehydration to give isoxazole derivatives 169 in high yields (Scheme 37) <2004T6453>. 

Treatment of nitrile oxide (71), obtainable from the xylopyranosylnitromethane, with the alkene (72) gave isoxazolines which were ring opened to the carbonyl-linked disaccharide analogues (73) and (74), the latter being produced following an epimerisation at C-2. ... 

Isoxazolines (52) and (53) were obtained from coupling of the xylose nitrile oxide (54) with the alkene (55) (Scheme 3). Reductive hydrolysis of these products gave the carbon-carbon linked disaccharides (56) and (57), the latter by way of a C-2 epimerisation during the reaction. ... 

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