反应详情

A solution of (R)-2-methyl-CBS-oxazaborolidine (7.5 mL of a 1 M soln in toluene, 7.5 mmol) in toluene (200 mL) was cooled in ice-salt bath (bath temp: −10° C.) under N2. To the solution was added BH3.SMe2 (17.1 mL, 180 mmol) over 3 min. Methyl 4-acetylbenzoate (26.4 g, 148 mmol) in THF (180 mL) was then added over 3 h via syringe pump. The bath temp remained at −10° C. throughout the addition. The reaction mixture was stirred for an additional 30 min, and then MeOH (100 mL) was added over 30 min (bath temp: −10° C.). The ice in the bath was allowed to melt and the reaction mixture was stirred overnight at RT. The reaction mixture was concentrated under reduced pressure, and the residue was diluted with EtOAc (500 mL). The organic solution was washed with 0.1 N HCl aq. (300 mL×4), 5% NaHCO3 (300 mL×2), saturated NaCl (300 mL×2) and dried over Na2SO4. Evaporation of the solvent afforded the title compound. MS (m/z): 181.1 (m+H).

1. additionTo the solution was added BH3
2. additionThe bath temp remained at −10° C. throughout the addition
3. stirringthe reaction mixture was stirred overnight at RT
4. concentrationThe reaction mixture was concentrated under reduced pressure
5. additionthe residue was diluted with EtOAc (500 mL)
6. washThe organic solution was washed with 0.1 N HCl aq. (300 mL×4), 5% NaHCO3 (300 mL×2), saturated NaCl (300 mL×2)
7. dry with materialdried over Na2SO4
8. customEvaporation of the solvent