ChemInform Abstract: Synthesis and Biological Evaluation of 3-Chloro-1-carbacephem Compounds.
Abstract
Starting with the 3H-1-carbacephem compounds (I), the 3-chlorocarbacephems (VIII) are synthesized by consecutive addition of thiophenol (II), oxidation of the sulfide (III), α-chlorination of the sulfoxide (IV), and elimination of phenylsulfinic acid from (V), followed by reduction of the azido group and hydrolysis of the tert-butyl ester.
ChemInform Abstract
Starting with the 3H-1-carbacephem compounds (I), the 3-chlorocarbacephems (VIII) are synthesized by consecutive addition of thiophenol (II), oxidation of the sulfide (III), α-chlorination of the sulfoxide (IV), and elimination of phenylsulfinic acid from (V), followed by reduction of the azido group and hydrolysis of the tert-butyl ester. Condensation reaction of 3-chlorocarbacephem (VIIIa) and its 2β-methyl analogue (VIIIb) with the 2-aminothiazole derivative (IX) gives the target products (X). The optically active compounds carbacefaclor (XIIa) and its p-hydroxy analog (XIIb) are prepared by enzymatic acylation of racemic (VIIIa). Carbacefaclor (XIIa) shows antibacterial activity against gram positive and gram negative bacteria. (Yields only partly given).
