Arylazo-glycenosides. Part 7. Syntheses of amino-sugars from methyl arylazo-hexenopyranosides

Abstract

Reaction of the anhydro-glycopyranosiduloses (1 ) and ( 2) with o-nitro-and o,p-dinitro-phenylhydrazine yielded the hydrazones (3)-( 6), whereas phenyl-or p-nitrophenyl-hydrazine yielded the phenylatoalkenes ( 7)-(lo), formed by rearrangement of intermediate hydrazones. Reaction of the azoalkanes ( 8) and ( 9) with a range of nuceophiles yielded the &-substituted phenylhydrazones (1 1 )-( 19) and ( 24)-( 28), respectively, by 1,4addition. It has been shown that the a-amino-hydrazones ( 20), ( 25), and ( 28) can be reduced to vicinal diaminosugars, thereby providing a new route to these compounds. Reduction of the azoalkene (9) yielded the 2-amino-2,3,6-trideoxy-hexopyranoside, isolated as the ON-diacetyl derivative (31 ). N SCHEME I ( O W s, 10.35 3.52 s, 10.12Ji,z J2.3