A note on groups covered by conjugates of a proper subgroup

In this paper we prove that if G is a group which is the union of the conjugates of a finite subgroup H, then we have G=H if H≃PSL(2,2n), n∈N∖{0} or H is a generalized dihedral group. This result extends Theorem 3 of Cutolo et al. (2005) [1] proved only in the case H≃PSL(2,4).