Preparation of homoallylic compounds by reaction of cyclopropylvinyl precursors with bronstedt acids

A method of forming homoallylic compounds 2 from cyclopropylvinyl precursors 1 in the presence of a Bronsted acid HQ

• wherein, the Bronsted acid HQ is selected from R′CO2H and/or a hydrogen halide selected from HCl, HBr or HI, wherein R is a C1-30 cyclic, polycyclic or acyclic alkyl residue, or an aryl or polyaryl residue, each of which may be saturated or unsaturated, branched or linear, and substituted or unsubstituted;
• R′ is a C1-30 alkyl or aryl residue, which may be linear or branched and may be substituted or unsubstituted, and wherein Q is R′CO2 and/or a halide atom.