Chlorotrimethylsilane → (2R)-5-hexyl-4-hydroxy-2-undecyl-2,3-dihydropyran-6-one

HRID 37543Notes

Reaction equation

HRID 37543 reaction equation
C1(O[C:8](=[O:33])[CH2:9][C@H:10]([O:22][C:23](=[O:32])[CH:24](Br)[CH2:25][CH2:26][CH2:27][CH2:28][CH2:29][CH3:30])[CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH3:21])C=CC=CC=1.Cl[Si](C)(C)C>[Zn].CCOCC>[CH2:25]([C:24]1[C:23](=[O:32])[O:22][C@H:10]([CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH3:21])[CH2:9][C:8]=1[OH:33])[CH2:26][CH2:27][CH2:28][CH2:29][CH3:30]

Participants

5

Reactant 2

HCID 6397ChlorotrimethylsilaneHCID 11016835Phenyl-(R)-3-(2-Bromo-1-Oxooctyloxy)Tetradecanoate

Product 1

HCID 54690023(2R)-5-hexyl-4-hydroxy-2-undecyl-2,3-dihydropyran-6-oneYield 67.3%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 3283Diethyl EtherSolvent

Procedure

In a flame-dried flask under N2 a mixture of 336 mg (5.14 mmol) zinc and 510 mg (0.99 mmol) (R)-3-[(2-bromo-1-oxoocty)oxy]tetradecanoic acid phenyl ester in 5.0 ml 20% v:v Et2O:chlorotrimethylsilane was heated at reflux with rapid stirring for 20 minutes. The mixture was cooled to room temperature and suction filtered through a coarse fritted funnel, using a pad of celite, and washing with 5 ml Et2O. The homogenous filtrate was cooled in an ice/H2O bath and 5 ml tap H2O was added with stirring. After 10 min, the mixture was poured into 50 ml tap H2O and extraction with 3×25 ml Et2O was performed. The combined organic layers were washed with 25 ml brine and dried over MgSO4. The Et2O was removed by rotary evaporation, giving a white solid. The solid was stirred with 6.0 ml hexanes for 30 min, followed by suction filtration through a medium fritted funnel. The product was washed with 2.0 ml hexanes and dried under 26" vacuum at room temperature for 1.5 h, giving 235 mg (67%) (R)-3-hexyl-5,6-dihydro-4-hydroxy-6-undecyl-2H-pyran-2-one as a white powder, mp=109°-111° C.; [α]20D=-43.5° (1% in dioxane).

Workup

  1. temperatureat reflux
  2. filtrationsuction filtered through a coarse fritted funnel
  3. washwashing with 5 ml Et2O
  4. temperatureThe homogenous filtrate was cooled in an ice/H2O bath
  5. additionwas added
  6. stirringwith stirring
  7. waitAfter 10 min
  8. additionthe mixture was poured into 50 ml
  9. extractionH2O and extraction with 3×25 ml Et2O
  10. washThe combined organic layers were washed with 25 ml brine
  11. dry with materialdried over MgSO4
  12. customThe Et2O was removed by rotary evaporation
  13. customgiving a white solid
  14. filtrationfollowed by suction filtration through a medium fritted funnel
  15. washThe product was washed with 2.0 ml hexanes
  16. customdried under 26" vacuum at room temperature for 1.5 h

Sources & evidence

ORD record
ord-bcb9a6d46aa348a482a8f2ca01b40b0c
Source dataset
uspto-grants-1995_05
Patent number
US05420305

Reaction notes

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