Isopropyl iodide → Methyl(1S,4S)-4-[(tert-Butoxycarbonyl)amino]-1-isopropylcyclopent-2-ene-1-carboxylate

HRID 270538Notes

Reaction equation

HRID 270538 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].[CH:28](I)([CH3:30])[CH3:29]>C1COCC1>[C:11]([O:15][C:16]([NH:18][C@H:19]1[CH2:23][C@@:22]([CH:28]([CH3:30])[CH3:29])([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 6362Isopropyl iodideHCID 2733832Lithium HexamethyldisilazideHCID 10610130(1R,4S)-methyl 4-(tert-butoxycarbonylamino)cyclopent-2-enecarboxylate

Product 1

HCID 60122269Methyl(1S,4S)-4-[(tert-Butoxycarbonyl)amino]-1-isopropylcyclopent-2-ene-1-carboxylateYield 77.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a 1.00 M solution of lithium hexamethyldisilazide in THF (202 mL) at −78° C. was added a solution of methyl (1R,4S)4-[(tert-butoxycarbonyl)amino]cyclopent-2-ene-1-carboxylate (22.10 g, 91.59 mmol) in THF (36.2 mL) over 10 min. The solution was stirred at −78° C. for 30 min before isopropyl iodide (10.0 mL, 100 mmol) was added in one portion. The mixture was then moved to a freezer reading at −24° C. and kept overnight. The reaction was quenched with aqueous ammonium chloride and the resulting solution was extracted with ether three times. The ether layers were dried over sodium sulfate and evaporated in vacuo. The residue was purified by flash chromatography on silica eluting with 10% ethyl acetate/hexane to give the title compound (20.2 g). MS calculated for C15H25NO4: (M+H)+ 284; found 184.2 (M-Boc+H)+.

Workup

  1. additionwas added in one portion
  2. customwas then moved to a freezer reading at −24° C.
  3. customThe reaction was quenched with aqueous ammonium chloride
  4. extractionthe resulting solution was extracted with ether three times
  5. dry with materialThe ether layers were dried over sodium sulfate
  6. customevaporated in vacuo
  7. customThe residue was purified by flash chromatography on silica eluting with 10% ethyl acetate/hexane

Sources & evidence

ORD record
ord-18b0ba10ff6843cbaeca63fd60c915d1
Source dataset
uspto-grants-2008_11
Patent number
US07449467B2

Reaction notes

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