Fluorine-Containing Butanolides and Butenolides. Vinylic Fluorine Displacement in 4,4-Dialkyl-2,3-difluoro-2-buten-4-olides and a Novel Rearrangement Induced by Organolithium Addition to a Carbonyl Group
3-substituted derivatives (4–24). Softer Grignard reagents in the form of a copper (I) bromide-dimethyl sulfide complex reacted in the same way as O-nucleophiles to afford 3-alkyl- or 3-aryl derivatives (25–26). Harder organolithium reagents attacked the carbonyl group to give unstable hydroxy compounds that rearranged spontaneously to furan(2H)-3-ones (27–29) in a novel oxygen rearrangement reaction.