Preheat oven to 350 degrees. Heat butter in rectangular 9"x13" pan, until melted. Sprinkle brown sugar in pan and then arrange orange slices. Sprinkle the sugar and oranges with coconut. Prepare cake mix, add the flour to the cake mix, and prepare it as directed, stirring in chopped pecans. Pour into pan and bake 45 to 55 minutes. Take out of the oven and immediately turn over.