In a large bowl, beat the sugar, buttermilk, oil, eggs and extract until well blended. Combine the flour, baking powder, baking soda and salt; gradually beat into sugar mixture until blended. Stir in coconut and walnuts.
Transfer to a greased and floured 10-in. fluted tube pan. Bake at 325° for 60-70 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes.
Meanwhile, in a small saucepan, bring sugar and water to a boil over medium heat. Cook and stir for 5 minutes or until slightly reduced. Remove from the heat; stir in butter and extract.
Remove cake from pan to a wire rack. Poke holes in warm cake with a skewer; slowly pour syrup over cake. Cool completely before cutting. Yield: 12 servings.