The acylation of 3',4'-dideoxykanamycin B (dibekacin) (I) with benzyloxycarbonyl chloride in water gives 6'-N-benzyloxycarbonyldibekacin (V), which is then acylated with (IV) as before and deprotected by hydrogenolysis with H2 over Pd/C in water - acetic acid.

The acylation of 3',4'-dideoxykanamycin B (dibekacin) (I) with N-benzyloxycarbonyloxysuccinimide (II) and zinc acetate in DMSO gives 3,2,6'-tri-N-benzyloxycarbonydibekacin (III), which is then treated with the N-hydroxysuccinimide ester of 2-hydroxy-4-aminobutyric acid (IV) and finally deprotected by hydrogenation with H2 over Pd/C in acidic water dioxane.

The acylation of 3',4'-dideoxykanamycin B (dibekacin) (I) with tert-butyl-S-(4,6-dimethylpyrimid-2-yl)thiocarbonate (VIII) by means of triethylamine in isopropanol gives 3,2',6'-tri-N-tert-butyloxycarbonyldibekacin (IX), which is acylated again with 4-benzyloxycarbonylamino-2-hydroxybutyric acid N-hydroxysuccinimide ester (X) in THE yielding the protected habekacin (XI). Finally, this compound is deprotected by a treatment with trifluoroacetic acid, followed by hydrogenolysis with H2 over Pd/C in methanol - acetic acid.

The acylation of 3',4'-dideoxykanamycin B (dibekacin) (I) with N-benzyloxycarbonyloxysuccinimide (II) and zinc acetate in DMSO gives 3,2,6'-tri-N-benzyloxycarbonydibekacin (III), which is then treated with the N-hydroxysuccinimide ester of 2-hydroxy-4-aminobutyric acid (IV) and finally deprotected by hydrogenation with H2 over Pd/C in acidic water dioxane.

The acylation of 3',4'-dideoxykanamycin B (dibekacin) (I) with benzyloxycarbonyl chloride in water gives 6'-N-benzyloxycarbonyldibekacin (V), which is then acylated with (IV) as before and deprotected by hydrogenolysis with H2 over Pd/C in water - acetic acid.

The acylation of 3,2,6'-tri-N-benzyloxycarbonydibekacin (III) with ethyl trifluoroacetate and K2CO3 gives 3,2',6'-tri-N-benzyloxycarbonyl-3''-trifluoroacetyldibekacin (VI), which is acylated again with (IV) yielding the protected habekacin (VII). Finally, this compound is deprotected by hydrolysis with ammonia in aqueous THF, followed by hydrogenolysis with H2 over Pd/C.

The acylation of 3',4'-dideoxykanamycin B (dibekacin) (I) with tert-butyl-S-(4,6-dimethylpyrimid-2-yl)thiocarbonate (VIII) by means of triethylamine in isopropanol gives 3,2',6'-tri-N-tert-butyloxycarbonyldibekacin (IX), which is acylated again with 4-benzyloxycarbonylamino-2-hydroxybutyric acid N-hydroxysuccinimide ester (X) in THE yielding the protected habekacin (XI). Finally, this compound is deprotected by a treatment with trifluoroacetic acid, followed by hydrogenolysis with H2 over Pd/C in methanol - acetic acid.

The acylation of 3',4'-dideoxy-3',4'-didehydrokanamycin B (XII) with tert-butyl-S-(4,6-dimethylpyrimid-2-yl)thiocarbonate (VIII) as before gives 3,2',6'-tri-N-butoxycarbonyl-3',4'-dideoxy-3',4'-didehydrokanamycin B (XIII), which is acylated again with (X) as before yielding the fully protected 3',4'-didehydrohabekacin (XIV). Partial deprotection of (XIV) with trifluoroacetic acid affords 1-N-(4-benzyloxycarbonylamino-2-hydroxybutyryl)-3',4'-dideoxy-3',4'-didehydrokanamycin B (XV), which is finally debenzylated and reduced by a treatment with H2 over PtO2 in aqueous acetic acid.

The acylation of 3,2,6'-tri-N-benzyloxycarbonydibekacin (III) with ethyl trifluoroacetate and K2CO3 gives 3,2',6'-tri-N-benzyloxycarbonyl-3''-trifluoroacetyldibekacin (VI), which is acylated again with (IV) yielding the protected habekacin (VII). Finally, this compound is deprotected by hydrolysis with ammonia in aqueous THF, followed by hydrogenolysis with H2 over Pd/C.