Combine flour, salt and pepper. Coat chicken pieces in flour mixture. Brown in hot oil. Drain pineapple, reserving juice. Combine juice, molasses, mustard, and vinegar, mix well. Place chicken in Dutch oven, arrange potatoes around chicken. Brush with half of the sauce. Cover and bake at 350 for 30 minutes. Top with pineapple, brush with remaining sauce, cook 30 min more.