ChemInform Abstract: Facile Conversion of Tetracycline Antibiotics to 4,11a‐Bridged Derivatives via Oxidative Mannich Cyclization.

Abstract

Facile Conversion of Tetracycline Antibiotics to 4,11a-Bridged Derivatives via Oxidative Mannich Cyclization. -The reaction of minocycline (I) with mercuric acetate proceeds with oxidation of a dimethylamino group followed by a novel intramolecular Mannich cyclization of an intermediate iminium cation leading to 4,11a-bridged derivative (II) in high yield. The oxidative Mannich cyclization of tigecycline, tetracycline and doxycycline is also described. -(GU, J.; CAI, P.; GONG, Y.; RUPPEN, M. E.; STORZ*, T.; J. Antibiot. 63 (2010) 12, 693-698, http://dx.doi.org/10.1038/ja.2010.119 ; Chem. Res. Dev., Pfizer Inc., Groton, CT 06340, USA; Eng.) -R. Staver 17-193