Studies related to penicillins. Part IX. Degradation of penicillanic acid derivatives by mercury(II) acetate

Abstract

Mercury(II) acetate in acetic acid converts 6β-phthalimidopenicillanic acid (5) into trans-4-acetoxy-1-(2-methyl-prop-1-enyl)-3-phthalimidoazetidin-2-one (17). Potassium benzylpenicillinate (10) and phenoxymethyl-penicillinic acid (11) undergo analogous reactions to yield the azetidinones (20) and (21), respectively.

Methyl 6β-phthalimidopenicillanate (6) and methyl benzylpenicillinate (12) are also degraded by mercury(II) acetate in acetic acid, to give trans-4-acetoxy-1-(1-methoxycarbonyl-2-methylprop-1-enyl)-3-phthalimidoazetidin-2-one (18) and trans-4-acetoxy-1-(1-methoxycarbonyl-2-methylprop-1-enyl)-3-phenylacetamidoazetidin-2-one (22), respectively.