Theoretical DFT calculations of the reaction between hexafluoro-2-butyne and dienes 3a - c were performed. The reaction starting with [4+2] cycloaddition of CF 3 C≡CCF 3 at one of the furan moieties occurs in a concerted fashion via TS1 and represents the rate limiting step of the whole process with the activation barrier Δ G ≈ 23.1–26.8 kcal/mol.