title: Chemical modifications in the tetracycline series.
abstract: New tetracycline analogs modified at position 5, 6 and 2 were synthetized. The 5-deoxy-5-oxo-derivatives, 2a and 3a, were obtained by DMSO/acetic anhydride oxidation of doxycycline (2) and methacycline (3), respectively; the 6-demethyl-6-hydroxymethyl-6-alpha-hydroxyoxytetracycline (3b) by methacycline oxidation with the KCIO3/OsO4 system and the 6-hydroxyanhydrooxytetracycline (4) treating 3b with periodic acid. The 2-ethoxycarbonyl-2-decarboxamidodoxycycline (2b), was synthesized by treating doxycycline nitrile (2c) with EtOH and anhydrous HCl, 2-thiocarboxamide-2-decarboxamidodoxycycline (2d) by reaction of doxycycline with P2S5 in dioxane and 2-aminomethyl-2-decarboxamidodoxycycline (2e) by RANEY-Nickel reduction of 2d. All the synthetized compounds proved to be almost inactive on agar plates both on Gram-positive and Gram-negative bacteria.
mesh_terms: D001419:Bacteria / Q000187:drug effects; D055598:Chemical Phenomena; D002621:Chemistry; D004352:Drug Resistance, Microbial; D013329:Structure-Activity Relationship; D013754:Tetracyclines / Q000138:chemical synthesis* / Q000494:pharmacology
chemical_list: D013754:Tetracyclines