Dimethyl Sulfoxide → tert-butyl (2S,4S)-4-(benzyloxymethyl)-5-methyl-1-oxohexan-2-ylcarbamate

HRID 660383Notes

Reaction equation

HRID 660383 reaction equation
CS(C)=O.C(Cl)(=O)C(Cl)=O.[CH2:11]([O:18][CH2:19][C@H:20]([CH:33]([CH3:35])[CH3:34])[CH2:21][C@H:22]([NH:25][C:26](=[O:32])[O:27][C:28]([CH3:31])([CH3:30])[CH3:29])[CH2:23][OH:24])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.C(N(CC)CC)C>C(Cl)Cl.O>[CH2:11]([O:18][CH2:19][C@H:20]([CH:33]([CH3:35])[CH3:34])[CH2:21][C@H:22]([NH:25][C:26](=[O:32])[O:27][C:28]([CH3:29])([CH3:30])[CH3:31])[CH:23]=[O:24])[C:12]1[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1

Participants

7

Reactant 4

HCID 679Dimethyl SulfoxideHCID 8471TriethylamineHCID 65578Oxalyl chlorideHCID 70642503tert-butyl (2S,4S)-4-(benzyloxymethyl)-1-hydroxy-5-methylhexan-2-ylcarbamate

Product 1

HCID 57195734tert-butyl (2S,4S)-4-(benzyloxymethyl)-5-methyl-1-oxohexan-2-ylcarbamateYield 99%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent3×

Procedure

A solution of DMSO (7.58 g, 97.2 mmol) in anhydrous CH2Cl2 (100 mL) was added dropwise to a stirred solution of oxalyl chloride (4.2 mL, 48.6 mmol) in anhydrous CH2Cl2 (150 mL) under N2 at −50° C. to −60° C. After 15 min, tert-butyl (2S,4S)-4-(benzyloxymethyl)-1-hydroxy-5-methylhexan-2-ylcarbamate (14.2 g, 40.5 mmol) in CH2Cl2 (100 mL) was added dropwise over 30 min, and stirred for about 60 min. Triethylamine (27 mL, 203 mmol) was added and the mixture was stirred overnight. Water was added, the organic layer was separated, and the aqueous layer was extracted with CH2Cl2. The combined organic layers were washed with 5% aq Na2CO3 and brine, dried over Na2SO4 and evaporated. The residue was purified by flash chromatography on silica gel to give tert-butyl (2S,4S)-4-(benzyloxymethyl)-5-methyl-1-oxohexan-2-ylcarbamate (14 g, 99%), which was used for next step without purification; MS: 350 (M++1).

Workup

  1. stirringthe mixture was stirred overnight
  2. customthe organic layer was separated
  3. extractionthe aqueous layer was extracted with CH2Cl2
  4. washThe combined organic layers were washed with 5% aq Na2CO3 and brine
  5. dry with materialdried over Na2SO4
  6. customevaporated
  7. customThe residue was purified by flash chromatography on silica gel

Sources & evidence

ORD record
ord-06a73a8061944e9fa7e7a4bf6ccdc2cf
Source dataset
uspto-grants-2011_12
Patent number
US08084485B2

Reaction notes

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