A solution of 4-bromo-9a-butyl-8-chloro-7-methoxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one (90 mg, 0.235 mmol) in anhydrous toluene (1.2 mL) was treated with tributyl(1-ethoxyvinyl)stannane (0.111 mL, 0.352 mmol) and bis(triphenylphosphine)palladium(II) chloride (33 mg, 0.047 mmol). The mixture was placed under a nitrogen atmosphere, stirred, and heated in an oil bath at 100° C. for 3 hours. After cooling to room temperature, the mixture was purified by preparative layer chromatography on two 0.1×20×20 cm silica gel GF plates, developing with 5% EtOAc in CH2Cl2. The product band was eluted with EtOAc and the eluent evaporated under vacuum to afford 9a-butyl-8-chloro-4-(1-ethoxyvinyl)-7-methoxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one (67 mg) as an oil.
