Cephalothin: Hydrolysis of the C-3'-acetoxy moiety of a 7-aminocephalosporanic acid; observation of both acyl-oxygen bond cleavage and reversible alkyl-oxygen bond cleavage

Article abstract of DOI:10.1002/jps.2600741106

The aqueous solution chemistry of the C-3'-acetoxy moiety of cephalothin sodium (1b) was examined with the use of isotopically labeled H₂¹⁸O and [2-¹³C]acetate anion. The ¹⁸O incorporation studies indicate that the hydrolysis (at pH 4.7 ± 0.1) of 1b to the deacetyl derivative of cephalothin (2b) proceeds via two pathways: alkyl-oxygen bond cleavage (55-63%) and acyl-oxygen bond cleavage accounting for the remainder. The incorporation of [2-¹³C]acetate into 1b suggests that the alkyl-oxygen cleavage pathway is a reversible reaction.