Reaction #1747891

Reaction equation

NMM

HOBt

DCC

L-proline benzyl ester

→

120

Yield 74.2%

N-Glycidyl-L-Proline Benzyl Ester

Yield 74.2%

Solvents

CH2Cl2

CH2Cl2

DMF

Conditions

Workup

1. 1
   workup.STIRRINGThe mixture was stirred 16 h at room temperature
2. 2
   Filtrationfiltered
3. 3
   Otherto remove the precipitate
4. 4
   workup.ADDITIONThe residue was diluted with CH2Cl2 (10 mL)
5. 5
   Washwashed with 10% KHSO4 (10 mL), 5% NaHCO3 (10 mL) and NaCl (10 mL, sat)
6. 6
   Dryingdried (Na2SO4)
7. 7
   Filtrationfiltered
8. 8
   Concentrationconcentrated
9. 9
   OtherThe crude oil was purified by column chromatography (silica gel, EtOAc/Hexanes 1/1)

Procedure

To a solution of L-proline benzyl ester (156 mg, 0.49 mmol) in DMF (2 mL), cooled to 0° C., NMM (56 μL, 0.53 mmol) and HOBt (198 mg, 1.47 mmol) were added. The solution was stirred at 0° C. for 15 minutes and a solution of glycidic acid21 (100 mg, 1.13 mmol) in CH2Cl2 (2 mL) was added. Finally a solution of DCC (253 mg, 1.23 mmol) in CH2Cl2 (2 mL) was added. The mixture was stirred 16 h at room temperature and filtered to remove the precipitate. The residue was diluted with CH2Cl2 (10 mL) and washed with 10% KHSO4 (10 mL), 5% NaHCO3 (10 mL) and NaCl (10 mL, sat), dried (Na2SO4), filtered and concentrated. The crude oil was purified by column chromatography (silica gel, EtOAc/Hexanes 1/1) to yield 120 (95 mg, 70%) as white foam. Rf 0.26 (AcOEt/Hexanes 1/1). 1H-NMR (500 MHz, CDCl3): mixture of rotamers 1.87-1.92 (m, 2H), 1.91-1.98 (m, 2H), 1.99-2.03 (m, 1H), 2.19-2.20 (m, 2H), 2.20-2.22 (m, 1H), 2.66-2.68 (m, 1H), 2.80-2.82 (m, 1H), 2.94-2.95 (m, 2H), 3.30-3.31 (m, 1H), 3.56-3.57 (m, 2H), 357-370 (m, 2H), 3.72-3.85 (m, 1H), 4.57-4.59 (m, 1H), 4.70-4.72 (m, 1H), 5.16 (s, 2H), 5.22-5.29 (m, 2H), 7.25-7.38 (m, 10H). 13C-NMR (125 MHz, CDCl3): 22.2, 24.9, 28.7, 30.9, 31.5, 45.9, 46.3, 46.4, 47.2, 48.0, 48.5, 58.7, 59.3, 66.9, 67.4, 128.1, 128.2, 128.4, 128.5, 128.7, 170.0, 182.3. HRMS m/z cald for C15H17NO4a (M+Na): 298.1055 found 298.1047.

Source