Place raspberries and syrup in a blender container or food processor bowl. Cover and blend or process until berries are smooth. Press berries through a fine-mesh sieve; discard seeds (you should have about 3/4 cup sieved puree).
In a pitcher combine raspberry puree, wine, and raspberry liqueur. Serve over ice, if desired. Makes 8 (about 4-ounce) servings.