摘要 |
<p>3'-Deoxykanamycin B, namely tobramycin is produced in an improved yield with a reduced reaction time under moderate reaction conditions, starting from a penta-N-protected 3'-mono-O-alkyl-, aralkyl- or arylsulfonylated derivative of kanamycin B in which all the 1, 3, 2' and 3''-amino groups and possibly the 6'-amino group have been protected by an arylsulfonyl group, especially tosyl group; the 3'-hydroxyl group of kanamycin B has been alkyl-, aralkyl- or arylsulfonylated; the 4''- and 6''-hydroxyl groups have been blocked with a di-valent hydroxyl-protecting group; and possibly the 4'-hydroxyl group and 6'-amino group have been blocked by being converted into the form of a 4', 6'-cyclic carbamate formed between the 4'-hydroxyl group and the 6'-amino group, by subjecting to a process essentially comprising reaction of said protected kanamycin B derivative with a metal halide for a reaction time of 30 min. to 2 hours at a reaction temperature of 0 DEG C. DIFFERENCE 150 DEG C. to produce the corresponding 3'-halo compound, reductive replacement of the 3'-halo group by hydrogen and deprotection.</p> |