At 1503 Central time the airplane collided with trees and the ground, and burst into flames during an attempted forced landing following a loss of engine power during cruise flight. Visual conditions prevailed; an IFR flight plan was filed. The Private pilot received serious injuries and the airplane sustained substantial damage. According to the pilot, the engine started running rough and then quit. There was oil on the left side of his windscreen. The pilot declared an emergency and ATC diverted him towards Guntersville, the closest airport. Shortly afterward, the pilot lost radio communications with ATC and became unsure of his position. He observed a field decided to land in it. Just prior to landing, the airplane struck trees, damaging the wings, and ended up on its back.