反应详情

To a solution of E2 (1.0 eq.) in THF (0.1 M solution) at −78° C. was added a solution of n-BuLi (1.3 eq.) in hexane. The solution was stirred for 30 min and then a solution of N-methoxy-N-methyl-7-(2-methyl-1,3-dioxolan-2-yl)heptanamide (1.5 eq.) in THF was slowly added. The reaction mixture was stirred for 1 hr at −78° C. and then 1 hr at RT. Then water was added and the aqueous phase was extracted with EtOAc. The combined organic extracts were dried (MgSO4) and the solvent was removed under reduced pressure. The crude was purified by column chromatography on silica gel eluting with 20-50% EtOAc/petroleum ether to obtain E3 as yellow solid. 1H NMR (300 MHz, CDCl3) δ: 8.32 (1H, s), 7.96-7.81 (4H, m), 7.68 (1H, s) 7.53-7.42 (2H, m), 5.85 (2H, s), 3.92 (4H, s), 3.64 (2H, t, J=8.2 Hz), 3.26 (2H, t, J=8.2 Hz), 1.77 (2H, m), 1.69-1.36 (8H, m), 1.31 (3H, s), 0.97 (2H, t, J=8.2 Hz), 0.19 (9H, s). MS (ES) C30H42N2O4Si requires: 522, found: 523 (M+H)+.

1. stirringThe reaction mixture was stirred for 1 hr at −78° C.
2. custom1 hr
3. customat RT
4. extractionthe aqueous phase was extracted with EtOAc
5. dry with materialThe combined organic extracts were dried (MgSO4)
6. customthe solvent was removed under reduced pressure
7. customThe crude was purified by column chromatography on silica gel eluting with 20-50% EtOAc/petroleum ether