Halogenation of fluoroalkyl-substituted β-ketoesters

1. The bromination of fluoroalkyl-substituted β-ketoesters using bromine gives unstable α-bromo derivatives which undergo intermolecular rearrangement to yield the starting β-ketoesters and α,α-dibromo-β-ketoesters. 2. An IR spectroscopic and dipole moment study showed that the z- and q-conformers relative to the ester C=0 bond are equally probable for the fluoroalkyl-substituted β-ketoesters.