反应详情

To a stirred and cooled (−78° C.) solution of the bromide 4 (5.00 g, 15.96 mmol) in Et2O (92 mL) was added dropwise 1.5 M solution of tert-butyllithium in pentane (22.3 mL, 33.5 mmol). After 45 min additional stirring at −78° C., DMF (5.6 mL, 72.3 mmol) was added dropwise, and the mixture was allowed to slowly warm to r.t. After 20 h the mixture was partitioned between saturated aqueous NaHCO3 solution and CH2Cl2. The organic layer was separated, dried (MgSO4), and concentrated to afford the crude aldehyde 13 (4.32 g). 1H NMR (400 MHz; CDCl3) δ 0.32 (s, 6H), 0.92 (s, 9H), 3.02 (m, 2H), 3.70 (m, 2H), 7.55 (d, J=2.0 Hz, 1H), 8.16 (d, J=2.0 Hz, 1H), 9.61 (s, 1H).

1. stirringAfter 45 min additional stirring at −78° C.
2. customAfter 20 h the mixture was partitioned between saturated aqueous NaHCO3 solution and CH2Cl2
3. customThe organic layer was separated
4. dry with materialdried (MgSO4)
5. concentrationconcentrated