1-[2-(4-Bromophenoxy)ethyl]piperidine → 5-(tert-butyl-dimethyl-silyloxy)-2-(7-(tert-butyl-dimethyl-silyloxy)-4-{1-hydroxy-1-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-ethyl}-2H-chromen-3-yl)-phenol

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-[2-(4-bromophenoxy)-ethyl]-piperidine (360 mg, 1.27 mmol) in THF (7.5 mL) at −78° C., was added n-butyl lithium (1.6 M in hexane, 773 μL, 1.24 mmol). The reaction mixture was stirred at −78° C. for 0.5 hours. To the reaction mixture was then added 2,8-bis-(tert-butyl-dimethyl-silyloxy)-11H-chromeno[4,3-c]chromen-5-one, prepared as in Example 22, (158 mg, 0.31 mmol) in THF (3 mL) and the mixture was stirred at −78° C. for 1.5 hours. To the reaction mixture was then added methyl magnesium bromide (3 M in diethyl ether, 1 mL, 3 mmol) at −78° C. and the reaction stirred at room temperature overnight. The reaction was quenched with aqueous NH4Cl and extracted with ethyl acetate. The organic layer was washed with brine and dried over MgSO4. The organic layer was concentrated to yield the crude title product as a yellow oil, which was carried into the next step without further purification.

Provenance & Evidence