Triphenylphosphine → (1Z,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 (R)-1-{(E,3S,3aS,7aR)-7-(bromomethylene)-octahydro-3a-methyl-1H-indene-3-yl}ethanol (Compound 19: 20.8 mg, 0.07613 mmol) and triphenylphosphine (50 mg, 0.1903 mmol) in tetrahydrofuran (0.35 ml) was cooled in an ice bath, and azodicarboxylic acid dimethyl ester (2.7 M in toluene, 73.3 μl, 0.1979 mmol) was added dropwise thereto. The reaction mixture was stirred at the same temperature for 5 minutes and at room temperature for 40 hours, and then evaporated under reduced pressure. The obtained crude product was purified by flash column chromatography to obtain (1Z,3aR,4E,7aS)-4-(bromomethylene)-1-ethylidene-octahydro-7a-methyl-1H-indene (13.4 mg, 69.1%).

Provenance & Evidence