Sodium, 2,4-cyclopentadien-1-yl- → HCID 58112235, compound

HRID 1942582Notes

Reaction equation

HRID 1942582 reaction equation
[CH-:1]1[CH:5]=[CH:4][CH:3]=[CH:2]1.[Na+].I[CH2:8][CH2:9][C:10]([O:12][CH3:13])=[O:11]>C(OCC)C.O1CCCC1>[C:1]1([CH2:8][CH2:9][C:10]([O:12][CH3:13])=[O:11])[CH2:5][CH:4]=[CH:3][CH:2]=1.[C:1]1([CH2:8][CH2:9][C:10]([O:12][CH3:13])=[O:11])[CH:5]=[CH:4][CH2:3][CH:2]=1

Participants

6

Conditions

Temperature
-78 °C

Procedure

The above compounds were prepared using a modified literature method (16). A 2.0 M solution of sodium cyclopentadienide in tetrahydrofuran (105.10 mL, 210.28 mmol) was added dropwise over 15 minutes to a stirred solution of methyl 3-iodopropionate (45.00 g, 210.28 mmol) in anhydrous diethyl ether (280 mL) and anhydrous tetrahydrofuran (200 mL) under nitrogen at −78° C. The resulting reaction mixture was stirred at −78° C. for 2 hours and then stored at −20° C. for a further 15 hours. The resulting red suspension was quenched with 1 M ammonium chloride solution (800 mL), and the organic phase was extracted with diethyl ether (5×400 mL). The combined organic layer was washed with 1 M ammonium chloride solution (2×500 mL) and dried (anhydrous sodium sulfate), filtered and concentrated in vacuo. The crude oil was purified by flash chromatography on silica using 5% ethyl acetate in iso-hexane to afford methyl 3-cylopenta-1,3-dienylpropionate (1-alkylCp) and methyl 3-cylopenta-1,4-dienylpropionate (2-alkylCp) (14.72 g, 96.72 mmol, 46%) as yellow liquids in a 1.2:1 ratio.

Workup

  1. customThe above compounds were prepared
  2. customThe resulting reaction mixture
  3. waitstored at −20° C. for a further 15 hours
  4. customThe resulting red suspension was quenched with 1 M ammonium chloride solution (800 mL)
  5. extractionthe organic phase was extracted with diethyl ether (5×400 mL)
  6. washThe combined organic layer was washed with 1 M ammonium chloride solution (2×500 mL)
  7. dry with materialdried (anhydrous sodium sulfate)
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo
  10. customThe crude oil was purified by flash chromatography on silica using 5% ethyl acetate in iso-hexane

Sources & evidence

ORD record
ord-bff05e4f96eb4796b1b7ba9c901f9f29
Source dataset
uspto-grants-2013_03
Patent number
US08389572B2

Reaction notes

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