A group of activists, claiming big corporaitons are too often above the law, yesterday demanded that California's attorney general dissolve Unocal Corp by invoking a rarely used state statute that would put the company out of business. The activists, including environmentalists, feminists and human rights advocates, also said they will look into dissolving the charters of other comapnies, but alleged Unocal (Union Oil Co of California) stood out for its record of violations.