Ethyl 3-oxocyclobutanecarboxylate → (+/-)-Ethyl 3-ethynyl-3-hydroxycyclobutane-1-carboxylate

HRID 575051Notes

Reaction equation

HRID 575051 reaction equation
Br[Mg][C:3]#[CH:4].[O:5]=[C:6]1[CH2:9][CH:8]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH2:7]1>O1CCCC1>[C:3]([C:6]1([OH:5])[CH2:9][CH:8]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH2:7]1)#[CH:4]

Participants

4

Reactant 2

HCID 22467070Ethyl 3-oxocyclobutanecarboxylateHCID 178418486HCID 178418486, compound

Product 1

HCID 86693087(+/-)-Ethyl 3-ethynyl-3-hydroxycyclobutane-1-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-70 °C

Procedure

This compound was prepared according to a procedure similar to that described in Procedure A. To a 100-mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed bromo(ethynyl)magnesium (0.5M in THF, 50 mL, 1.20 equiv). This was followed by the addition of a solution of ethyl 3-oxocyclobutane-1-carboxylate (3.0 g, 21.10 mmol, 1.00 equiv) in tetrahydrofuran (3 mL) dropwise with stirring at −70° C. in 15 min. The resulting solution was stirred for 30 min at −70° C. The reaction was then quenched by the addition of 10 mL of sat. aq. ammonium chloride. The resulting solution was extracted with 3×20 mL of ethyl acetate and the organic layers combined and dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (1:10). This resulted in 2.6 g (66%) of ethyl 3-ethynyl-3-hydroxycyclobutane-1-carboxylate as light yellow oil (single undetermined diastereomer).

Workup

  1. customThis compound was prepared
  2. customTo a 100-mL 3-necked round-bottom flask purged
  3. temperaturemaintained with an inert atmosphere of nitrogen
  4. stirringThe resulting solution was stirred for 30 min at −70° C
  5. customThe reaction was then quenched by the addition of 10 mL of sat. aq. ammonium chloride
  6. extractionThe resulting solution was extracted with 3×20 mL of ethyl acetate
  7. dry with materialdried over anhydrous sodium sulfate
  8. concentrationconcentrated under vacuum
  9. customThis resulted in 2.6 g (66%) of ethyl 3-ethynyl-3-hydroxycyclobutane-1-carboxylate as light yellow oil (single undetermined diastereomer)

Sources & evidence

ORD record
ord-4d0127ba497247d5ae3fe2e2ddbfe3fb
Source dataset
uspto-grants-2015_05
Patent number
US09034866B2

Reaction notes

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