Roll pastry 1 inch larger than pan. Line pan with pastry. Fold overhang and crimp along edge of pan. Peel, core and quarter apples; cut into thick wedges. Heat syrup and salt to the boiling point. Add half the apple slices, and simmer until apples are slightly glazed, 5 to 7 minutes. Repeat with remaining apples. Remove apples from syrup; arrange in rows on pastry so that slices overlap slightly. Sprinkle on raisins. Let butter melt in syrup, then pour over apples. Bake 25 to 30 minutes, or until pastry is cooked and apples are slightly browned.