9-Borabicyclo(3.3.1)nonane → (S)-3-cyclohexyl-1-propyn-3-ol

HRID 2118571Notes

Reaction equation

HRID 2118571 reaction equation
C12BC(CCC1)CCC2.[CH:10]1([C:16](=[O:19])[C:17]#[CH:18])[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1>O1CCCC1.CC1[C@H]2C(C)(C)[C@H](C2)CC=1>[CH:10]1([C@H:16]([OH:19])[C:17]#[CH:18])[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1

Participants

5

Reactant 2

HCID 789669-Borabicyclo(3.3.1)nonaneHCID 103517531-Cyclohexyl-2-propyn-1-one

Product 1

HCID 10307864(S)-3-cyclohexyl-1-propyn-3-olYield 69%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 440968(-)-alpha-PineneSolvent

Conditions

Temperature
0 °C

Procedure

A mixture of 1.6 liters of 0.5M 9-borabicyclo[3.3.1]nonane in tetrahydrofuran and 122.6 g (-)-α-pinene, 99+% pure, was heated at reflux under nitrogen for 4 hr., at which time the excess (-)-α-pinene and tetrahydrofuran were removed under vacuum to leave a thick oil. The contents of the flask were cooled to 0° C. and 80 g of 3-cyclohexyl-1-propyn-3-one, prepared according to Preparation 6, was added with stirring. The resulting mixture was allowed to warm to 23° C. and it was stirred at that temperature for 16 hr. Excess S-Alpine borane was destroyed by adding 44 ml propionaldehyde and stirring at 23° C. for 1 hr. The liberated (-)-α-pinene was removed by vacuum distillation. The resulting mixture was diluted with 400 ml tetrahydrofuran followed by 300 ml 3N sodium hydroxide. To this stirred mixture was added in dropwise fashion 300 ml 30% hydrogen peroxide over 1 hr. The mixture was heated at 40° C. for 3 hr. After cooling, the mixture was extracted with diethyl ether and this extract was dried over magnesium sulfate. Evaporation of the solvent and purification of the residue by silica gel flash chromatography using 5% ethyl acetate-hexane gave 56 g of (S)-3-cyclohexyl-1-propyn-3-ol, which by nmr analysis was shown to have 90%, e.e. Recrystallization from hexane gave 45 g of the pure S isomer, mp 56°-58°, [α]D25 =-9.24° (C=0.53, Et2O).

Workup

  1. temperature99+% pure, was heated
  2. temperatureat reflux under nitrogen for 4 hr
  3. custom, at which time the excess (-)-α-pinene and tetrahydrofuran were removed under vacuum
  4. customto leave a thick oil
  5. customaccording to Preparation 6
  6. additionwas added
  7. temperatureto warm to 23° C.
  8. stirringit was stirred at that temperature for 16 hr
  9. customExcess S-Alpine borane was destroyed
  10. additionby adding 44 ml propionaldehyde
  11. stirringstirring at 23° C. for 1 hr
  12. customThe liberated (-)-α-pinene was removed by vacuum distillation
  13. additionThe resulting mixture was diluted with 400 ml tetrahydrofuran
  14. additionTo this stirred mixture was added in dropwise fashion 300 ml 30% hydrogen peroxide over 1 hr
  15. temperatureThe mixture was heated at 40° C. for 3 hr
  16. temperatureAfter cooling
  17. extractionthe mixture was extracted with diethyl ether
  18. dry with materialthis extract was dried over magnesium sulfate
  19. customEvaporation of the solvent and purification of the residue by silica gel flash chromatography

Sources & evidence

ORD record
ord-4d76b192abec49b2bea6572536726f55
Source dataset
uspto-grants-1987_07
Patent number
US04678805

Reaction notes

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