Ethyl diazoacetate → HCID 18648007, compound

HRID 974432Notes

Reaction equation

HRID 974432 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([CH:12]=[CH2:13])[CH2:10][OH:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].[N+](=C[C:17]([O:19][CH2:20][CH3:21])=[O:18])=[N-].[Si:22]([O:29][Si:30]([C:33]([CH3:36])([CH3:35])[CH3:34])([CH3:32])[CH3:31])([C:25]([CH3:28])([CH3:27])[CH3:26])([CH3:24])[CH3:23]>CCOCC.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[Si:22]([O:29][Si:30]([C:33]([CH3:36])([CH3:35])[CH3:34])([CH3:31])[CH3:32])([C:25]([CH3:27])([CH3:28])[CH3:26])([CH3:24])[CH3:23].[C:1]([O:5][C:6]([NH:8][C@H:9]([C:12]1([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:23][CH2:13]1)[CH2:10][OH:11])=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

7

Reactant 3

HCID 12192Ethyl diazoacetateHCID 590018TBDMS etherHCID 10965250HCID 10965250, compound

Product 2

HCID 590018TBDMS etherHCID 18648007HCID 18648007, compoundYield 87.9%

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalyst2×HCID 3283Diethyl EtherSolvent2×

Procedure

Palladium(II) acetate (168 mg, 0.75 mmol) was dissolved in an ether solution (50 ml) of t-butyldimethylsilyl ether of (2R)-N-t-butoxycarbonyl-2-amino-3-butenol (3) (4.34 g, 15.0 mmol) and to this was added an ether solution (100 ml) of ethyl diazoacetate (17.1 g, 150 mmol) and palladium(II) acetate (168 mg, 0.75 mmol) over 3 hours. The insoluble material in the reaction mixture was filtered off and the filtrate was concentrated under reduced pressure to give an oily product. Purification of the product by column chromatography over silica gel (20% ether/hexane) afforded t-butyldimethylsilyl ether of (2R)-N-t-butoxycarbonyl-2-(ethoxycarbonylcyclopropyl)glycinol (4) as an oil (4.00 g, 87.9%). Compound (4) thus obtained was dissolved in ethanol (70 ml) and CSA (10 mg) was added to this solution then the mixture was stirred for 16 hours at room temperature. The solvent was removed under reduced pressure and the residue was subjected to medium pressure column chromatography over silica gel (50% ether/hexane) 932 mg of (2R,3S,4S)-N-t-butoxycarbonyl-2-(ethoxycarbonylcyclopropyl)glycinol (5), 175 mg of its stereoisomer (6) and 560 mg of a mixture of inseparable stereoisomer.

Workup

  1. filtrationThe insoluble material in the reaction mixture was filtered off
  2. concentrationthe filtrate was concentrated under reduced pressure
  3. customto give an oily product
  4. customPurification of the product by column chromatography over silica gel (20% ether/hexane)

Sources & evidence

ORD record
ord-2e5eb023bc1e4b3fb87f44ff4b44ef81
Source dataset
uspto-grants-1991_11
Patent number
US05068412

Reaction notes

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