Triphenylphosphine → (1E,3aR,4E,7aS)-4-(bromomethylene)-1-ethylidene-octahydro-7a-methyl-1H-indene

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Reaction Steps

Under a nitrogen atmosphere, a solution of (S)-1-{(E,3S,3aS,7aR)-7-(bromomethylene)-octahydro-3a-methyl-1H-indene-3-yl}ethanol (Compound 18: 52.4 mg, 0.1918 mmol) and triphenylphosphine (126 mg, 0.4795 mmol) in tetrahydrofuran (0.3 ml) was cooled in an ice bath, and azodicarboxylic acid diethyl ester (2.2 M in toluene, 223.4 μl, 0.4915 mmol) was added dropwise thereto. The reaction mixture was stirred in the ice bath for 10 minutes and at room temperature for 21 hours, and then evaporated under reduced pressure. The obtained crude product was purified by flash column chromatography to obtain (1E,3aR,4E,7aS)-4-(bromomethylene)-1-ethylidene-octahydro-7a-methyl-1H-indene (21.8 mg, 44.6%).

Provenance & Evidence