反应详情

A round bottom flask was charged with (CH3)3S(I)O (37.9 g, 172.4 mmol, 2 eq.) and DMSO (450 mL). With moderate stirring under N2, a clear yellow solution was formed. To this solution was added sodium tert-butoxide (16.5 g, 172.4 mmol, 2 eqs) and the resultant mixture was stirred at RT for 2 h. 21A (20 g, 86.2 mmol, 1 eq) was charged and the container of the acrylate was rinsed forward with DMSO (50 mL). Stirring of the reaction mixture was continued at RT for 16 h. The reaction mixture was analyzed for completion using 1H NMR spectroscopy. After confirming completion of the reaction, the reaction mixture was diluted by sequential addition of MTBE (500 mL) and brine (300 mL). The organic layer was separated, dried over MgSO4 and evaporated to dryness to give crude product. The crude product was purified by flash chromatography, eluting with 5-10% EtOAc in heptanes to give 11.6 g 21B (54% yield) (which was found by 1H NMR to contain a small amount of impurities). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.23-1.29 (m, 1H) 1.49 (s, 9H) 1.57-1.69 (m, 1H) 1.83-1.96 (m, 1H) 2.40-2.53 (m, 1H), 7.18 (d, 2H) 7.56 (d, 2H).

1. customa clear yellow solution was formed
2. washthe container of the acrylate was rinsed forward with DMSO (50 mL)
3. stirringStirring of the reaction mixture
4. customcompletion of the reaction
5. customThe organic layer was separated
6. dry with materialdried over MgSO4
7. customevaporated to dryness
8. customto give crude product
9. customThe crude product was purified by flash chromatography
10. washeluting with 5-10% EtOAc in heptanes