title: Single enantiomer synthesis of α-(trifluoromethyl)-β-lactam.
abstract: The first synthesis of α-(trifluoromethyl)-β-lactam ((S)-1) is reported. The route starts from α-(trifluoromethyl)acrylic acid (2). Conjugate addition of α-(p-methoxyphenyl)ethylamine ((S)-3b), generated an addition adduct 4b which was cyclised to β-lactam 5b. Separation of the diastereoisomers by chromatography gave ((αS,3S)-5b). N-Debenzylation afforded the desired α-(trifluoromethyl)-β-lactam ((S)-1). The absolute stereochemistry of diastereoisomers 5 was determined by X-ray crystallographic determination of a close structural analogue, (αS,3S)-5c, and then (1)H and (19)F NMR correlation to the individual diastereoisomers of 5a and 5b.
authors.affiliation: EASTChem School of Chemistry and Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK.
authors.forename: Václav
authors.initials: V
authors.lastname: Jurčík
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin
authors.forename: David
authors.initials: D
authors.lastname: O'Hagan