Iodoethane → Methyl(1R,4S)-4-[(tert-Butoxycarbonyl)amino]-1-ethylcyclopent-2-ene-1-carboxylate

HRID 1044615Notes

Reaction equation

HRID 1044615 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].I[CH2:29][CH3:30]>C1COCC1>[C:11]([O:15][C:16]([NH:18][C@H:19]1[CH2:23][C@@:22]([CH2:29][CH3:30])([C:24]([O:26][CH3:27])=[O:25])[CH:21]=[CH:20]1)=[O:17])([CH3:14])([CH3:13])[CH3:12]

Participants

5

Reactant 3

HCID 6340IodoethaneHCID 2733832Lithium HexamethyldisilazideHCID 10610130(1R,4S)-methyl 4-(tert-butoxycarbonylamino)cyclopent-2-enecarboxylate

Product 1

HCID 59833554Methyl(1R,4S)-4-[(tert-Butoxycarbonyl)amino]-1-ethylcyclopent-2-ene-1-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a 1.00 M solution of lithium hexamethyldisilazide in THF (61.5 mL, 61.5 mmol) was added a solution of methyl (1R,4S)-4-[(tert-butoxycarbonyl)amino]cyclopent-2-ene-1-carboxylate (6.71 g, 27.8 mmol) in THF (10.0 mL) at −78° C. over 10 min. The resulted light brown solution was stirred at −78° C. for 30 min before iodoethane (2.67 mL, 33.4 mmol) was added in one portion. The mixture was then kept at −25° C. overnight. The reaction was quenched with aqueous NH4Cl. The organic layer was separated and the aqueous layer was further extracted with ether three times. The combined organic layers were then washed with brine, dried over Na2SO4, filtered, concentrated and purified by flash column chromatography to yield the desired product as a 7:1 cis/trans mixture (4.83 g, 65%). MS calculated for C14H23NO4: (M+H) 170.2; found 170.1 (M+H-Boc).

Workup

  1. additionwas added in one portion
  2. customThe reaction was quenched with aqueous NH4Cl
  3. customThe organic layer was separated
  4. extractionthe aqueous layer was further extracted with ether three times
  5. washThe combined organic layers were then washed with brine
  6. dry with materialdried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated
  9. custompurified by flash column chromatography

Sources & evidence

ORD record
ord-478f7877b7614490b136ee6ae885233d
Source dataset
uspto-grants-2013_10
Patent number
US08563582B2

Reaction notes

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