Tetrahydrofuran → HCID 15409727, compound

HRID 1699976Notes

Reaction equation

HRID 1699976 reaction equation
C[Si](C[Li])(C)C.[Li].ClC[Si](C)(C)C.[CH3:14][C:15]1[C:16](=O)[C:17]([CH3:25])([CH3:24])[CH2:18][CH:19]2[C:23]=1[O:22][CH2:21][O:20]2.[O:27]1CCC[CH2:28]1>CCCCC>[CH2:25]=[CH:17][CH2:18][CH2:19][C:23]([OH:27])=[O:22].[CH3:14][C:15]1[C:16](=[CH2:28])[C:17]([CH3:25])([CH3:24])[CH2:18][CH:19]2[C:23]=1[O:22][CH2:21][O:20]2

Participants

8

Reactant 5

HCID 8028TetrahydrofuranHCID 75361Silane, (chloromethyl)trimethyl-HCID 3028194LithiumHCID 18370006HCID 18370006, compoundHCID 178418939HCID 178418939, compound

Product 2

HCID 611384-Pentenoic acidHCID 15409727HCID 15409727, compoundYield 82%

Reagents, catalysts & solvents 1

HCID 8003PentaneSolvent

Procedure

The solution of trimethylsilylmethyllithium (about 0.43 mol) prepared from 8.7 g (1.25 mol) of lithium powder and 74 ml (61.6 g, 0.5 mol) of chloromethyltrimethylsilane in 450 ml of pentane was placed in a 750 ml four-necked sulphonation flask provided with a magnetic stirrer, dropping funnel, condenser and argon gasification. Then a solution of 60.0 g (0.33 mol) of 4,6,6-trimethyl-5,6,7,7a-tetrahydro-1,3-benzodioxol-5-one in 75 ml of tetrahydrofuran was added dropwise thereto at −20° C. within 30 minutes. The mixture was warmed slowly to room temperature and subsequently the pentane was distilled off up to the boiling point 62° C. over a Vigreux column. The pentane, which was distilled off, was replaced continuously with 500 ml of tetrahydrofuran. Finally, the mixture was heated at reflux for 12 hours under GC control. Subsequently, it was cooled to 0° C., 200 ml of water were added dropwise, the phases were separated and the aqueous phase was extracted three times with 100 ml of pentane each time. The entire organic phase was washed with 150 ml of saturated sodium bicarbonate solution and sodium chloride solution, dried over anhydrous sodium sulphate, filtered and concentrated. This gave 67.5 g of a yellow oil, which was distilled over a 10 cm packed column. At a boiling temperature of 38° C./0.04 mbar (4 Pa) there were obtained 49.0 g (82% yield) of 4,6,6-trimethyl-5,6,7,7a-tetrahydro-5-methylidene-1,3-benzodioxol as a colorless oil. The analytical data of the product were the same as those of the product of Example 7.

Workup

  1. customwas placed in a 750 ml four-necked sulphonation flask
  2. customprovided with a magnetic stirrer
  3. distillationsubsequently the pentane was distilled off up to the boiling point 62° C. over a Vigreux column
  4. distillationThe pentane, which was distilled off
  5. temperatureFinally, the mixture was heated
  6. temperatureat reflux for 12 hours under GC control
  7. temperatureSubsequently, it was cooled to 0° C.
  8. addition200 ml of water were added dropwise
  9. customthe phases were separated
  10. extractionthe aqueous phase was extracted three times with 100 ml of pentane each time
  11. washThe entire organic phase was washed with 150 ml of saturated sodium bicarbonate solution and sodium chloride solution
  12. dry with materialdried over anhydrous sodium sulphate
  13. filtrationfiltered
  14. concentrationconcentrated
  15. distillationThis gave 67.5 g of a yellow oil, which was distilled over a 10 cm

Sources & evidence

ORD record
ord-41f123c5b5794a608612a075685c2ab8
Source dataset
uspto-grants-2002_02
Patent number
US06348606B2

Reaction notes

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