Butyl iodide → 2-butyl-6-methoxy-3,4-dihydro-1(2H)-naphthalenone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 6-methoxy-3,4-dihydro-1(2H)-naphthalenone (5.29 g, 30 mmol) in anhydrous tetrahydrofuran (THF, 150 mL) was placed under a N2 atmosphere, cooled in an ice bath, stirred, and treated with lithium diisopropylamide (90 mL of a 0.4M solution in THF, 36 mmol) dropwise over 13 minutes. The mixture was stirred at 0-5° C. for 30 minutes, then cooled in a dry ice-acetone bath to −78° C. and treated all at once with iodobutane (17.04 mL, 150 mmol). The resulting mixture was allowed to slowly warm to room temperature and stirred at room temperature overnight. The mixture was quenched with saturated aqueous NH4Cl and concentrated under vacuum. The residue in EtOAc was washed with 5% NaHCO3 and brine, dried over MgSO4, filtered, and evaporated under vacuum. The crude product was purified by Biotage™ (Charlottesville, Va.) flash chromatography on a 40M (4×15 cm) silica gel column, eluting successively with 1000 mL portions of 0.1%, 0.2%, 1%, 2%, and 5% EtOAc in hexane. The product-containing fractions were evaporated under vacuum to afford 2-butyl-6-methoxy-3,4-dihydro-1(2H)-naphthalenone as an oil.

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