Heat oil in a pan and fry the pork chops until light brown for at least 3 minutes on each side. Then transfer the pork chops in a baking pan without the oil.
In a saucepan, combine catsup, water, sugar and vinegar. Bring to a boil and simmer until the sugar in dissolved. Season with salt and pepper.
Pour the sauce over the pork chops and also top with the pineapple slices. Include also the pineapple syrup on the pork chops.
Cover with an aluminum foil and bake in a preheated oven 275°F for 3 hours or until the pork is tender. Serve hot.