Diazomethane → (1R,2S)-ethyl 1-(tert-butoxycarbonylamino)-2-cyclopropylcyclopropanecarboxylate

HRID 500338Notes

Reaction equation

HRID 500338 reaction equation
[C:1]([NH:8][C@:9]1([C:14]([OH:16])=[O:15])[CH2:11][C@H:10]1[CH:12]=[CH2:13])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].[N+](=C)=[N-].[C:20](OCC)(=O)[CH3:21].[CH3:26]CCCCC>C(OCC)C.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[CH2:20]([O:15][C:14]([C@@:9]1([NH:8][C:1]([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2])[CH2:11][C@H:10]1[CH:12]1[CH2:26][CH2:13]1)=[O:16])[CH3:21]

Participants

6

Reactant 3

HCID 9550DiazomethaneHCID 10376443(1R,2S)-1-(((1,1-Dimethylethoxy)carbonyl)amino)-2-ethenylcyclopropanecarboxylic acidHCID 21226206Ethyl acetate hexane

Product 1

HCID 59990838(1R,2S)-ethyl 1-(tert-butoxycarbonylamino)-2-cyclopropylcyclopropanecarboxylateYield 78%

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 3283Diethyl EtherSolvent2×

Procedure

A solution of N-Boc-(1R,2S)-1-amino-2-vinylcyclopropane carboxylic acid (255 mg, 1.0 mmol) in diethyl ether (10 mL) was treated with palladium acetate (5 mg, 0.022 mmol). The orange/red solution was placed under a nitrogen atmosphere. An excess of diazomethane in diethyl ether was added dropwise over the course of 1 hour. The resulting solution was stirred at room temperature for 18 hours. The excess diazomethane was removed using a stream of nitrogen and the resulting solution was concentrated by rotary evaporation to give the crude product. Flash chromatography (10% ethyl acetate/hexane) provided 210 mg (78%) of (1R,2S)—N-Boc-1-amino-2-cyclopropylcyclopropane carboxylic acid ethyl ester as a colorless oil. MS m/z 270 (M++H).

Workup

  1. customThe excess diazomethane was removed
  2. concentrationthe resulting solution was concentrated by rotary evaporation
  3. customto give the crude product

Sources & evidence

ORD record
ord-f8c4cd9c65c1464995138107ecdce85a
Source dataset
uspto-grants-2010_08
Patent number
US07772180B2

Reaction notes

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