Lewis acid mediated addition of 1, 8-bis (trimethylsilyl) octa-2, 6-diene (BISTRO) 1 to succinic anhydride led to spirolactone 2 [(±)-6, 9-divinyl-1-oxaspiro [4.4] nonan-2-one]. Methoxycarbonylation followed by stereoselective alkylation by various benzocyclobutenes afforded the substituted benzocyclobutene steroid precursors 5. Thermolysis of 5 gave rise to steroids (±)-6 with a trans-anti-cis configuration in five steps and in a highly ...