Cleavage of chiral 4-phenyl-2-oxalidinones with TMSI: Application to the synthesis of carbacephems

A Novel Strategy Towards Aminophosphonic Derivatives Based on the Diels-Alder Cycloaddition: Experimental and Theoretical Approaches

“…Removal of the chiral auxiliary [82][83][84], phosphonate hydrolysis, and other functionalization / cleavage of the cyclohexene moiety [48] should provide novel enantiomerically pure aminophosphonic derivatives. On the basis of ab initio calculations, we postulated that the replacement of the carbonyl oxygen by a sulphur atom should enhance the selectivity of the cycloaddition process.…”

A Study on the Asymmetric Synthesis of β-Lactams through Double Stereodifferentiating Cycloaddition Reactions

“…In view of the recent methods for recovering 6e,f and/or cleaving oxazolidinone chiral auxiliaries, we next evaluated the behavior of ketenes derived from 2b and 2c in such a cycloaddition process with the aim of establishing whether bulkier groups at the C 3 position of the oxazolidinone moiety might exert some influence in directing the stereochemical course of the reaction …”

4-Phenyloxazolidin-2-ones and isoindolin-1-ones: chiral auxiliaries for Diels–Alder reactions of N-substituted 1,3-dienes

“…[41][42][43][44] Clearly, this procedure was incompatible with the highly oxidised functionality present in molecules 26-29. The Fischer method for oxazolidinone cleavage, 45 using trimethylsilyl iodide looked ideal, but in our hands with substrate 27 this led only to intractable material. Unfortunately removal of the auxiliaries in these substrates is not a trivial task.…”