40693-00-3Relevant academic research and scientific papers
Reactivite des α-halobutyrolactones a halogenes tertieres vis-a-vis des nucleophiles faiblement basiques
Gharbi-Benarous, Josyane,Essayegh, Mounir M.,Dana, Gilbert
, p. 2031 - 2038 (2007/10/02)
2-Methyl-4-phenylbutenolide (5) is prepared in a quantitative manner by an elimination of HBr from the corresponding bromolactones 3.This reaction, induced by halide ions at 100 deg C in polar aprotic solvents (DMF, DMSO), is acoompanied by a bimolecular nucleophilic substitution.In these reactions, the solvent seems able to play an active role.A polar solvent induces the necessary activation of the substrate (by a prior strong polarization of the C-Br bond).In the absence of the halide ions, a solvolytic reaction takes place.As soon as the elimination reaction produces enough halide ions, the bimolecular reaction takes over.The activation of the chloroacetones 4 is much more difficult than that of the bromolactones 3; however, each elimination is of the E2ip type with some E2C type.
