66316-99-2Relevant academic research and scientific papers
Thiazolidine Ring Opening in Penicillin Derivatives. Part 2. Enamine Formation
Davis, Andrew M.,Layland, Nicola J.,Page, Michael I.,Martin, Frances,O'Ferrall, Rory More
, p. 1225 - 1229 (2007/10/02)
The alkaline hydrolysis of (3S,5R,6R)-methyl benzylpenicilloate, and the corresponding carboxamide and N-ethylamide, is accompanied by an absorbance increase at 285 nm.This is attributed to a competing elimination reaction across C6-C5 to open the thiazolidine ring and reversibly generate an enamine intermediate.Kinetic analysis and hydrolysis in D2O do not indicate a significant buildup of this intermediate during hydrolysis of the methyl ester.However, over the pH range 4-11 the rate of thiazolidine ring opening is competitive with hydrolysis of the ester function.The deuterium solvent kinetic isotope effect on the ring closure reaction is 7.5.
