反应详情

To a solution of LDA (7.0 mL, 14 mmol, 2M solution in THF/ethylbenzene) in THF (10 mL) was added a solution of 1,4-dioxa-spiro[4.5]decane-8-carboxylic acid ethyl ester (Compound 282H, 2.14 g, 9.99 mmol) in THF (5 mL) at −78° C. under nitrogen. The resulting mixture was stirred at this temperature for 30 min, then a solution of methyl iodide (1.98 g, 14.0 mmol) in THF (5 mL) was added. The resulting mixture was slowly warmed to rt overnight. The reaction was quenched with sat. aq. NH4Cl (20 mL) and diluted with EtOAc (50 mL). The organic layer was washed with brine (30 mL), and dried over anhydrous sodium sulfate. The solvents were evaporated under reduced pressure to give the desired compound as a light-yellow oil, 2.30 g, 100% yield. The material was used in next step without further purification. 1H NMR (CDCl3): 1.20 (s, 3H), 1.26 (t, J=7.1 Hz, 3H), 1.52-1.68 (m, 6H), 2.12-2.17 (m, 2H), 3.94 (s, 4H), 4.15 (q, J=7.1 Hz, 2H).

1. customThe reaction was quenched with sat. aq. NH4Cl (20 mL)
2. additiondiluted with EtOAc (50 mL)
3. washThe organic layer was washed with brine (30 mL)
4. dry with materialdried over anhydrous sodium sulfate
5. customThe solvents were evaporated under reduced pressure