Acetone → Methyl (1R,4S)-4-[(tert-butoxycarbonyl)amino]-1-(1-hydroxy-1-methylethyl)cyclopent-2-ene-1-carboxylate

HRID 1436806Notes

Reaction equation

HRID 1436806 reaction equation
C[Si](C)(C)[N-][Si](C)(C)C.[Li+].[C:11]([O:15][C:16]([NH:18][C@H:19]1[CH2:23][C@@H:22]([C:24]([O:26][CH3:27])=[O:25])[CH:21]=[CH:20]1)=[O:17])([CH3:14])([CH3:13])[CH3:12].C(Cl)(Cl)(Cl)Cl.C(=O)=O.[CH3:36][C:37]([CH3:39])=[O:38]>C1COCC1>[C:11]([O:15][C:16]([NH:18][C@H:19]1[CH2:23][C@@:22]([C:37]([OH:38])([CH3:39])[CH3:36])([C:24]([O:26][CH3:27])=[O:25])[CH:21]=[CH:20]1)=[O:17])([CH3:14])([CH3:13])[CH3:12]

Participants

6

Reactant 4

HCID 180AcetoneHCID 2733832Lithium HexamethyldisilazideHCID 10610130(1R,4S)-methyl 4-(tert-butoxycarbonylamino)cyclopent-2-enecarboxylateHCID 86602444Carbontetrachloride dry-ice

Product 1

HCID 59833557Methyl (1R,4S)-4-[(tert-butoxycarbonyl)amino]-1-(1-hydroxy-1-methylethyl)cyclopent-2-ene-1-carboxylateYield 22.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

To a 1.00 M solution of lithium hexamethyldisilazide in THF (45 mL) stirring at −78° C. was added a solution of methyl (1R,4S)-4-[(tert-butoxycarbonyl)amino]cyclopent-2-ene-1-carboxylate (5.0 g, 21 mmol) in THF (40 mL). The resulting golden mixture was warmed to −28° C. to −23° C. (CCl4/dry ice) and stirred for 30 min. The reaction solution was cooled down to −78° C. and anhydrous acetone (1.8 mL, 25 mmol) was added. After the addition, the reaction mixture was kept in a CCl4/dry ice bath and allowed to warm to room temperature overnight. The dark solution was quenched with saturated NH4Cl and extracted with ether three times. The combined extracts were dried, filtered, concentrated. The crude residue was purified by flash column chromatography (EtOAc/Hexane) to yield the desired product (1.4 g, 22.6%).

Workup

  1. additionAfter the addition
  2. customthe reaction mixture was kept in a CCl4/dry ice bath
  3. temperatureto warm to room temperature overnight
  4. customThe dark solution was quenched with saturated NH4Cl
  5. extractionextracted with ether three times
  6. customThe combined extracts were dried
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe crude residue was purified by flash column chromatography (EtOAc/Hexane)

Sources & evidence

ORD record
ord-b20bd38853c842d0b045c7a58e33761e
Source dataset
uspto-grants-2009_11
Patent number
US07618970B2

Reaction notes

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