89024-21-5Relevant articles and documents
SYNTHESES OF β-LACTAMS BY RING CONTRACTION OF ISOTHIAZOLIDINONES
Easton, Christopher J.
, p. 153 - 158 (2007/10/02)
Several methods have been developed for the preparation of β-lactams from isothiazolidinones.Oxidation of 2-t-butyl-4,4-diphenyl- and 2,4,4-trimethyl-isothiazolidin-3-ones (4a) and (4b) with sulphuryl chloride afforded the 5-chloroisothiazolidinones (5a) and (5b), which were converted into 1-t-butyl-3,3-diphenyl- nd 1,3,3-trimethyl-4-phenylthioazetidin-2-ones (6a) and (6b) by treatment with phenyl-lithium.Alternatively, reaction of the isothiazolidinones (4a) and (4b) with phenyl-lithium gave N-t-butyl-2,2-diphenyl- and N,2,2-trimethyl-3-phenylthiopropionamides(12a) and (12b), which were transformed into the β-lactams (6a) and (6b) by halogenation at C-3, followed by treatment with potassium amide.These are examples of methods used to prepare β-lactams from isothiazolidinones.The verstility of these reactions and their relevance to penicilin biosynthesis is discussed.