L-Leucine, N-((1,1-dimethylethoxy)carbonyl)- → Boc-L-leucinol

HRID 2270148Notes

Reaction equation

HRID 2270148 reaction equation
[NH:1]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[C@H:2]([C:7](O)=[O:8])[CH2:3][CH:4]([CH3:6])[CH3:5]>C1COCC1.[Cl-].[Na+].O>[C:10]([NH:1][C@H:2]([CH2:7][OH:8])[CH2:3][CH:4]([CH3:5])[CH3:6])([O:12][C:13]([CH3:14])([CH3:16])[CH3:15])=[O:11]

Participants

4

Reactant 1

HCID 83170L-Leucine, N-((1,1-dimethylethoxy)carbonyl)-

Product 1

HCID 7018766Boc-L-leucinolYield 89.1%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent3×HCID 57417360Sodium chloride; waterSolvent

Conditions

Temperature
23 °C

Procedure

To a solution of BOC-Leu-OH (15.09 g, 65 mmol, 1 equiv) in THF (150 mL) at 0° C. was added BH3. THF (163 mL of a 1.0 M solution in THF, 163 mmol, 2.51 equiv). The reaction mixture was stirred at 23° C. for 3 h and then cooled to 0° C. Brine (100 mL) was added carefully, and the aqueous layer was extracted with EtOAc (2×100 mL). The combined organic layers were dried over Na2SO4 and concentrated. The residue was purified by flash column chromatography (gradient elution, 25-35% EtOAc in hexanes) to afford BOC-L-Leucinol as a colorless oil (12.59 g, 89%): IR (cm−1): 3434, 1699, 1256, 739; 1H NMR (CDCl3) δ 0.93 (dd, 6H, J=6.6, 1.5), 1.29-1.31 (m, 2H), 1.45 (s, 9H), 1.60-2.05 (m, 2H), 3.47-3.53 (m, 1H), 3.65-3.72 (m, 2H), 4.56 (s, br, 1H); Anal. (C11H23NO3) C, H, N.

Workup

  1. temperaturecooled to 0° C
  2. extractionthe aqueous layer was extracted with EtOAc (2×100 mL)
  3. dry with materialThe combined organic layers were dried over Na2SO4
  4. concentrationconcentrated
  5. customThe residue was purified by flash column chromatography (gradient elution, 25-35% EtOAc in hexanes)

Sources & evidence

ORD record
ord-47a775b000ea4e74a72cc2ffebc70fa1
Source dataset
uspto-grants-2001_12
Patent number
US06331554B1

Reaction notes

Loading…