Methanol → tert-butyl (2S,4S)-4-(benzyloxymethyl)-1-hydroxy-5-methylhexan-2-ylcarbamate

HRID 507836Notes

Reaction equation

HRID 507836 reaction equation
[CH2:1]([O:8][CH2:9][C@H:10]([CH:26]([CH3:28])[CH3:27])[CH2:11][C@H:12]([NH:18][C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20])[CH2:13]C(OC)=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[BH4-].[Li+].C[OH:32]>O1CCCC1>[CH2:1]([O:8][CH2:9][C@H:10]([CH:26]([CH3:28])[CH3:27])[CH2:11][C@H:12]([NH:18][C:19](=[O:20])[O:21][C:22]([CH3:25])([CH3:24])[CH3:23])[CH2:13][OH:32])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 887MethanolHCID 4148881Lithium borohydrideHCID 68623312methyl 4(S)-benzyloxymethyl-2(S)-tert-butoxycarbonylamino-5-methylhexanecarboxylate

Product 1

HCID 70642503tert-butyl (2S,4S)-4-(benzyloxymethyl)-1-hydroxy-5-methylhexan-2-ylcarbamate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

The stirred solution of 5.0 g of methyl 4(S)-benzyloxymethyl-2(S)-tert-butoxycarbonylamino-5-methylhexanecarboxylate [CAS 180182-92-7] in 80 ml of tetrahydrofuran is admixed in portions with 0.660 g of lithium borohydride. The reaction mixture is stirred for another 3 hours, admixed cautiously with 25 ml of methanol and concentrated by evaporation at 40° C. The residue is dissolved once more in 70 ml of methanol and again concentrated by evaporation at 40° C. The residue is admixed with 1M HCl (cold) and extracted with dichloromethane (3×). The combined organic phases are washed with water, dried over sodium sulphate, filtered and concentrated by evaporation. The title compound is obtained from the residue by means of flash chromatography (SiO2 60F) as a colourless oil. Rf=0.32 (1:1 EtOAc-heptane); Rt=4.86 (gradient I).

Workup

  1. concentrationconcentrated by evaporation at 40° C
  2. dissolutionThe residue is dissolved once more in 70 ml of methanol
  3. concentrationagain concentrated by evaporation at 40° C
  4. extractionextracted with dichloromethane (3×)
  5. washThe combined organic phases are washed with water
  6. dry with materialdried over sodium sulphate
  7. filtrationfiltered
  8. concentrationconcentrated by evaporation

Sources & evidence

ORD record
ord-e034e51d4304480183ff755b96f9a76d
Source dataset
uspto-grants-2010_08
Patent number
US07786307B2

Reaction notes

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