| 摘要 |
<p>PURPOSE:To prepare the title compound having excellent antibacterial activity to resistant bacteria, by reacting tylosin with an aliphatic carboxylic acid anhydride, treating the reaction product (novel compound) with a lower alkanol containing ammonia, and finally heating the treated product in methanol, etc. CONSTITUTION:A novel compound I (R1,2 are 2-6C alkanoyl; R3 is 2-6C alkanoyl or halo-lower-alkanoyl) is treated with a lower alkanol containing ammonia to eliminate the protecting groups of the 3- and 4''-positions. The product is, without particular purification, heated in (hydrous) methanol or ethanol to eliminate the protecting group of the 2'-position to obtain the objective compound. The novel compound I can be prepared by (1) reacting tylosin with a 2-6C aliphatic carboxylic acid anhydride in the presence of an inorganic base such as alkali carbonate, at 40-60 deg.C, (2) pouring the reaction product into water, (3) adjusting the pH of the solution to 8-10, and (4) extracting with a non-hydrophilic organic solvent.</p> |
