Abstract
Treatment of the 1,6-anhydrosugar epoxide 5 with a cyano-Gilman cuprate [(CuCN (6 eq.), MeLi (12 eq.)] surprisingly led to the open chain rearranged (2S,3R)-1,2-dihydroxy-3,6-dimethylheptan-4-one (7), structurally confirmed by conversion to the corresponding diacetate 8. Another unusual reaction was found by hydrogenation of the 2-tosyl-1-bromosugar 11, leading in one operation to the twofold deoxygenated chiral pyran derivative 14. This procedure might prove to be useful in the rapid deoxygenation of sugar derivatives.