Synthesis and Rearrangement Reactions of C-Alkylidene Carbohydrates

Direct: olefinations on one hand in comparison to eliminations of aldols cf various uloses on the other each proved to be specific as to the sice of unsaturation in the branched-chain products, found to be interconvertible with one exception under a variety of conditions. Although shown to be generally equivalent to its Witcig-counterpart:, the Peterson reagent employed is liable to cause eliminations in the initial olefin. One of the branched-chain products appears to be of unusual molecular rigidity as evidenced by a large 5J coupling.