Water → HCID 15409727, compound

HRID 1532502Notes

Reaction equation

HRID 1532502 reaction equation
[H-].[K+].[CH3:3][C:4]1[C:5]([CH2:16][Si](C)(C)C)(O)[C:6]([CH3:14])([CH3:13])[CH2:7][CH:8]2[C:12]=1[O:11][CH2:10][O:9]2.O>O1CCCC1>[CH3:3][C:4]1[C:5](=[CH2:16])[C:6]([CH3:14])([CH3:13])[CH2:7][CH:8]2[C:12]=1[O:11][CH2:10][O:9]2

Participants

5

Reactant 3

HCID 962WaterHCID 82127Potassium hydrideHCID 18370002HCID 18370002, compound

Product 1

HCID 15409727HCID 15409727, compoundYield 78.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
25 °C

Procedure

23 ml (about 1 eq.) of potassium hydride (20% in oil) were placed in a 750 four-necked sulphonation flask provided with a magnetic stirrer, dropping funnel and argon gasification, washed three times with hexane and 120 ml of tetrahydrofuran were added. A solution of 30.4 g (0.11 mol) of 4,6,6-trimethyl-5,6,7,7a-tetrahydro-5-trimethylsilylmethyl-1,3-benzodioxol-5-ol in 200 ml of tetrahydrofuran was added dropwise thereto at 0° C. Subsequently, the suspension was stirred at 20-30° C. for 2 hours. It was again cooled to 0° C. and 200 ml of water were cautiously added dropwise. Subsequent three-fold extraction with 100 ml of hexane each time, washing with saturated sodium chloride solution and drying over anhydrous sodium sulphate gave, after removal of the solvent under reduced pressure, 18.7 g of yellow oil which was subjected to short path distillation under reduced pressure. At 77-85° C./0.75 mbar (7.5 kPa) there were obtained 15.6 g (74% yield) of 4,6,6-trimethyl-5,6,7,7a-tetrahydro-5-methylidene-1,3-benzodioxol as a colorless oil. The content of desired product was 96% according to GC (area %). IR (film, cm−1): 1697, 1600; mass spectrum: 180 (M+, 50), 107 (100); 1H-NMR (C6D6, 400 MHz): inter alia 0.83 and 0.95 (2s, in each case 3H), 1.78 (bs, 3H), 3.9 (m, 1H), 4.59 (s, 1H), 4.79 (s, 1H), 4.75 (s, 1H), 4.91 (s 1H).

Workup

  1. customprovided with a magnetic stirrer
  2. washargon gasification, washed three times with hexane and 120 ml of tetrahydrofuran
  3. additionwere added
  4. customat 0° C
  5. temperatureIt was again cooled to 0° C.
  6. extractionSubsequent three-fold extraction with 100 ml of hexane each time
  7. washwashing with saturated sodium chloride solution
  8. dry with materialdrying over anhydrous sodium sulphate
  9. customgave
  10. customafter removal of the solvent under reduced pressure, 18.7 g of yellow oil which
  11. distillationwas subjected to short path distillation under reduced pressure

Sources & evidence

ORD record
ord-3a4978aadf124ad2b50c9315bac93a2b
Source dataset
uspto-grants-2001_03
Patent number
US06201155B1

Reaction notes

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