合成路线1

In a different procedure, starting from negamycin (I), protection with benzyl S-(4,6-dimethylpyrimidin-2-yl)thiol carbonate (II) yields the bis-(benzyloxycarbonyl) derivative (III). Subsequent esterification of acid (III) employing diazomethane leads to methyl ester (IV). The free hydroxyl group of (IV) is then converted to the mesylate (V) by means of methanesulfonyl chloride in cold pyridine. Further mesylate group displacement in (V) with NaI gives rise to the alkyl iodide (VI). Finally, simultaneous cleavage of the N-carbobenzoxy groups and iodide hydrogenolysis in (VI) is accomplished by hydrogenation in the presence of Pd/BaCO3.