Hydrochloric Acid → 7,7-Ethylenedioxy-3-methyl-2,4-octadienal

HRID 2352381Notes

Reaction equation

HRID 2352381 reaction equation
Br[CH:2]=[C:3]([CH3:11])[CH:4]=[CH:5][O:6][Si](C)(C)C.C([Li])(C)(C)C.[CH2:17]1[CH2:25][O:24][C:19]([CH3:23])([CH2:20][CH:21]=O)[O:18]1.Cl>CCCCC.C(OCC)C.O>[CH2:17]1[CH2:25][O:24][C:19]([CH3:23])([CH2:20][CH:21]=[CH:2][C:3]([CH3:11])=[CH:4][CH:5]=[O:6])[O:18]1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 110079262-(2-Methyl-1,3-dioxolan-2-yl)acetaldehydeHCID 540133491-Bromo-2-methyl-4-trimethylsilyloxybutadieneHCID 178418306HCID 178418306, compound

Product 1

HCID 544179667,7-Ethylenedioxy-3-methyl-2,4-octadienalYield 55%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent3×HCID 8003PentaneSolvent

Conditions

Temperature
-70 °C

Procedure

Anhydrous ethyl ether (11 cc) and 1-bromo-2-methyl-4-trimethylsilyloxy-1,3-butadiene (0.9 g) are introduced under an argon atmosphere into a 50-cc round-bottomed flask. This is cooled to -70° C. and then a solution (3.25 cc) of 1.65M tert-butyllithium in pentane is added over 10 minutes. The mixture is stirred at -70° C. for 100 minutes and 3,3-ethylenedioxybutanal (0.4 g) is then added in solution in anhydrous ethyl ether (4 cc). The temperature is allowed to rise to -30° C. and stirring is performed for 30 minutes. Further stirring is performed for 20 minutes at -20° C. and then the mixture is cooled to -60° C. N Hydrochloric acid (11.5 cc) is added over 20 minutes. The temperature is allowed to rise to about 20° C. After the reaction mixture has been taken up with ether and water and the organic phases have been dried over magnesium sulphate, and after flash chromatography, 7,7-ethylenedioxy-3-methyl-2,4-octadienal (0.33 g) is obtained, its characteristics being as follows:

Workup

  1. customto rise to -30° C.
  2. stirringstirring
  3. waitis performed for 30 minutes
  4. stirringFurther stirring
  5. waitis performed for 20 minutes at -20° C.
  6. temperaturethe mixture is cooled to -60° C
  7. customto rise to about 20° C
  8. dry with materialthe organic phases have been dried over magnesium sulphate

Sources & evidence

ORD record
ord-4454cbaf3069475091351ab6ed5600a1
Source dataset
uspto-grants-1989_10
Patent number
US04876370

Reaction notes

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