Abstract: The propellane 12-oxatricyclo [4.4. 3.01~ 6] trideca-3, 8-diene (81) undergoes two consecutive Diels-Alder reactions, the first intermolecular and the second intramolecular, with the regenerable diene tetrachlorothiophene 1, l-dioxide to give 1 l-oxa-2, 3, 4, 5- tetrachlorohexacyclo [7.6. 1. 16~ 13.0 z~ 7.05 J5. 09J3]-3-heptadecane (41). Related propellanes undergo similar reactions.