The private pilot landed at an airport 45 miles short of his destination to refuel. No fuel was available, so he elected to continue to his destination. He estimated 12 gallons of fuel on board at the time. Enroute to the airport, he ran the right tank dry, and switched to the left tank. He decided to fly a no flap landing due to low fuel. He was high and fast on final, so he slipped the aircraft, left wing low. He could not land safely, so he executed a go around, and the engine did not respond. He attempted a turn back to the airport for a forced landing. While in the turn, the aircraft struck a fence, then collided with the ground. The Cessna 210 pilot's manual states that prolonged sideslips can result in unporting of the fuel system, and fuel starvation. There can be up to 10 gallons of unusable fuel in the system when level flight is not maintained. The engine power loss occurred about 35 minutes into the accident flight.