Sodium borohydride → (R)-tert-Butyl(1((2-(hydroxymethyl)benzyl)oxy)pent-4-en-2-yl)carbamate

HRID 1429381Notes

Reaction equation

HRID 1429381 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([CH2:23][CH:24]=[CH2:25])[CH2:10][O:11][CH2:12][C:13]1[CH:22]=[CH:21][CH:20]=[CH:19][C:14]=1[C:15](OC)=[O:16])=[O:7])([CH3:4])([CH3:3])[CH3:2].[Cl-].[Cl-].[Ca+2].[BH4-].[Na+]>CCO.C1COCC1>[C:1]([O:5][C:6](=[O:7])[NH:8][C@H:9]([CH2:23][CH:24]=[CH2:25])[CH2:10][O:11][CH2:12][C:13]1[CH:22]=[CH:21][CH:20]=[CH:19][C:14]=1[CH2:15][OH:16])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 4311764Sodium borohydrideHCID 5284359Calcium ChlorideHCID 68233281(R)-Methyl 2-(((2-((tert-butoxycarbonyl)amino)pent-4-en-1-yl)oxy)methyl)benzoate

Product 1

HCID 68233280(R)-tert-Butyl(1((2-(hydroxymethyl)benzyl)oxy)pent-4-en-2-yl)carbamateYield 78%

Reagents, catalysts & solvents 1

HCID 21873804Tetrahydrofuran ethanolSolvent

Procedure

A solution of compound 18h (4.2 g, 12.0 mmol) in EtOH/THF (30 mL, v/v=1/1) was treated with CaCl2 (5.3 g, 48.0 mmol) and the resulting slurry was cooled under argon in an ice bath. To this mixture was added NaBH4 (3.6 g, 96 mmol) portionwise. After 1 h the ice bath was removed and the reaction mixture was allowed to stir at rt for 16 hr. The mixture was quenched with 10% aq. Na2CO3 and water and the resulting thick, white slurry was extracted with EtOAc (3×50 mL). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated. The crude product was purified by CC to give the desired compound 18i (3.0 g, 78% yield) as yellow oil. LCMS (m/z): 322.1 (MH+).

Workup

  1. temperaturethe resulting slurry was cooled under argon in an ice bath
  2. customAfter 1 h the ice bath was removed
  3. customThe mixture was quenched with 10% aq. Na2CO3 and water
  4. extractionthe resulting thick, white slurry was extracted with EtOAc (3×50 mL)
  5. washThe combined organic layers were washed with brine
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated
  8. customThe crude product was purified by CC

Sources & evidence

ORD record
ord-e7655289b79e4147bded19122b615906
Source dataset
uspto-grants-2015_01
Patent number
US08940722B2

Reaction notes

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