Abstract: Density functional theory computations elucidated the ring opening of benzoannulated derivatives of bicycle[4.1.0]hept-7-ylidene (6). The B3LYP geometry optimizations and single-point energies employed a 6-31G (d) basis set. The ring opening barrier leading to cycloallenes, 11 and 15 is predicted to be 11.11 and 9.52 kcal/mol, respectively, which are lower than that for the ring opening of cyclopropylidene 6 (15.1 kcal/mol). This explains that 11 and 15 could be generated if Doering-Moore-Skattebol reaction is carried out for this purpose.