Peel the pineapple and, leaving it whole, cut out the center core. Slice into 8 rings, and place them in a shallow glass dish or resealable plastic bag. In a small bowl, mix together the rum, brown sugar, cinnamon, ginger, nutmeg, and cloves. Pour marinade over the pineapple, cover, and refrigerate for 1 hour, or overnight.
Preheat grill for high heat. Lightly oil grate.
Grill pineapple rings 15 minutes, turning once, or until outside is dry and char marked. Serve with remaining marinade.