tert-Butanol → (S)-2-methyl-4-methylidene-3-(2-propynyl)cyclopent-2-ene-1-ol

HRID 1079005Notes

Reaction equation

HRID 1079005 reaction equation
[C:1](O)(C)(C)C.CC(C)([O-])C.[K+].[CH3:12][C:13]1[C@@H:17]([OH:18])[CH2:16][C:15](=O)[C:14]=1[CH2:20][C:21]#[CH:22].P([O-])(O)(O)=O.[Na+]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.CCOCC>[CH3:12][C:13]1[C@@H:17]([OH:18])[CH2:16][C:15](=[CH2:1])[C:14]=1[CH2:20][C:21]#[CH:22]

Participants

7

Reactant 4

HCID 6386tert-ButanolHCID 1569974-Hydroxy-3-methyl-2-(prop-2-yn-1-yl)cyclopent-2-en-1-oneHCID 23665647Potassium tert-butoxideHCID 23672064Monosodium phosphate

Product 1

HCID 11829602(S)-2-methyl-4-methylidene-3-(2-propynyl)cyclopent-2-ene-1-ol

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 3283Diethyl EtherSolvent2×

Procedure

Ether (70 ml), t-butanol (6.6 ml) and methyltriphenylphosphonium bromide (25 g) were mixed with stirring at room temperature, then potassium t-butoxide (12.9 g) was added to the mixture and then the resulting solution was stirred for 5 hours at the same temperature. To the solution was added a solution of (S)-3-methyl-2-(2-propynyl)-4-hydroxycyclopent-2-ene-1one (12.42 g) in ether (13 ml) under ice-water cooling and the resulting reaction mixture was stirred at the same temperature for 2 hours and then for 6 hours at room temperature. The reaction solution was poured into a saturated aqueous solution of sodium dihydrogenphosphate, and extracted with ether. The obtained ether layer was washed with brine and dried over anhydrous magnesium sulfate. Then the filtered solution was evaporated. The obtained oily residue was then subjected to silica gel column chromatography, however, neither the desired product, (S)-2-methyl-4-methylidene-3-(2-propynyl)cyclopent-2-ene-1-ol nor the starting material was obtained.

Workup

  1. stirringthe resulting solution was stirred for 5 hours at the same temperature
  2. customthe resulting reaction mixture
  3. stirringwas stirred at the same temperature for 2 hours
  4. extractionextracted with ether
  5. washThe obtained ether layer was washed with brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. customThen the filtered solution was evaporated

Sources & evidence

ORD record
ord-8aef7ceff4d545dfa23aacad2158acfb
Source dataset
uspto-grants-1996_08
Patent number
US05550260

Reaction notes

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