反应详情

To a solution of ZnEt2 (110 mg, 0.844 mmol) in dry DCM (2 mL) was added DME (distilled, 0.088 mL, 844 mmol). The reaction mixture was stirred at rt for 10 min under N2, then cooled to −20° C. and CH2I2 (0.137 mL, 1.687 mmol) was added dropwise over 4 min. After stirring for 10 min, a solution of the alkene 8b (149 mg, 0.281 mmol) in dry DCM (1 mL) was added dropwise over 5 min. The reaction mixture was allowed to warm to rt while stirring. After 10 h, the reaction mixture was quenched with sat. aq. NH4Cl and diluted with DCM and water, the aqueous phase was separated and extracted with EtOAc. The combined organic layers were dried (Na2SO4), filtered and concentrated in vacuo. Flash chromatography (SiO2, 9:1, hexanes/Et2O) afforded 785 mg (68%) of the title compound as a colorless oil. 1H NMR analysis showed only 1 diastereomer (>95:5 dr). [α]D23−26.8 (c 1.0, DCM); 1H NMR (300 MHz, CDCl3) δ 7.73-7.66 (m, 4H), 7.48-7.28 (m, 11H), 5.13-4.96 (m, 2H), 4.62 (appbd, 1H, J=8.4 Hz), 3.72 (appbt, 2H, J=6.4 Hz), 3.21 (m, 1H), 1.80-1.63 (m, 1H), 1.60-1.25 (m, 4H), 1.08 (s, 9H), 0.92 (appd, 6H, J=6.3 Hz), 0.79 (m, 1H), 0.51 (m, 1H), 0.40 (m, 1H), 0.30 (m, 1H); HRMS (ESI) m/z calcd for C34H45NO3SiNa 566.3066; found 566.3103.

1. temperaturecooled to −20° C.
2. stirringAfter stirring for 10 min
3. temperatureto warm to rt
4. stirringwhile stirring
5. waitAfter 10 h
6. customthe reaction mixture was quenched with sat. aq. NH4Cl
7. additiondiluted with DCM and water
8. customthe aqueous phase was separated
9. extractionextracted with EtOAc
10. dry with materialThe combined organic layers were dried (Na2SO4)
11. filtrationfiltered
12. concentrationconcentrated in vacuo