Lithium diisopropylamide → 3-[5-(Benzo[b]thien-2-yl)2,4-dimethoxyphenyl]-1-(4-tert-butyldimethylsiloxy-3,5-dimethoxyphenyl)-2-propen-1-one

Participants

Reaction Steps

Ex-59B: To a solution of 3′,5′-dimethoxy-4′-(tert-butyldimethylsiloxy)acetophenone, from Ex-59A (0.5 g, 1.6 mmol) in tetrahydrofuran (10 mL) chilled with ice/water was added lithium diisopropylamide (2 M, 0.8 mL, 1.6 mmol). The mixture was stirred for 20 minutes while chilled. Then 5-(benzo[b]thien-2-yl)-2,4-dimethoxybenzaldehyde, from Ex-6A,(0.48 g, 1.6 mmol) in tetrahydrofuran (6 mL) was added, and the mixture was stirred at room temperature for 2 hours. Upon quenching with water, the mixture was extracted with dichloromethane. The organic phase was dried and evaporated. Crystallization from ethanol gave 0.19 g (20%) of the desired 3-[5-(benzo[b]thien-2-yl)2,4-dimethoxyphenyl]-1-(4-ter-butyldimethylsiloxy-3,5-dimethoxyphenyl)-2-propen-1-one as a yellow solid.

Provenance & Evidence