4-Bromo-5-(bromomethylidene)-3-(1-hydroxybutyl)furan-2(5H)-one → HCID 69230687, compound

HRID 1829948Notes

Reaction equation

HRID 1829948 reaction equation
[Br:1][C:2]1[C:6](=[CH:7][Br:8])[O:5][C:4](=[O:9])[C:3]=1[CH:10]([OH:14])[CH2:11][CH2:12][CH3:13].CC(C)=O.OS(O)(=O)=O.O=[Cr](=O)=O>CC(C)=O.S(=O)(=O)(O)O.O.[O-2].[O-2].[O-2].[Cr+6]>[Br:1][C:2]1[C:6](=[CH:7][Br:8])[O:5][C:4](=[O:9])[C:3]=1[C:10](=[O:14])[CH2:11][CH2:12][CH3:13]

Participants

7

Reactant 2

HCID 571699464-Bromo-5-(bromomethylidene)-3-(1-hydroxybutyl)furan-2(5H)-oneHCID 131709961Jones' reagent

Product 1

HCID 69230687HCID 69230687, compound

Reagents, catalysts & solvents 4

HCID 10219390chromium (VI) trioxideCatalystHCID 180AcetoneSolventHCID 962WaterSolvent2×HCID 1118Sulfuric AcidSolvent

Procedure

To an ice cooled solution of 4-bromo-5-(bromomethylene)-3-(1-hydroxybutyl)-2(5H)-furanone (2.77 g, 8.5 mmol) in acetone (75 ml) was added dropwise with stirring Jones reagent (12 ml, prepared by dissolving chromium trioxide (13.36 g) in sulfuric acid (11.2 ml) and water (38.5 ml). The mixture was stirred at room temperature for 1 h and the progress of the reaction monitored by thin layer chromatography. After the completion of the reaction, the mixture was poured into water (200 ml) and extracted with ether (3×100 ml). The combined ether extracts were washed with brine (100 ml), dried over sodium sulfate and evaporated to yield the crude ketone (2.23 g, 81%) as a yellow solid. Recrystallisation of the crude ketone from dichloromethane/hexane gave the pure ketone as yellow plates, m.p. 83–84° C. νmax 1700, 1680, 1630, 1540, 1310, 1000 cm−1. 1H n.m.r. δ (CDCl3) 0.97, t, J 7.2 Hz, (H4′)3; 1.70, m, (H3′)2; 2.93, t, J 7.2 Hz, (H2′)2; 6.74, s, 5-CHBr. 13C n.m.r. δ (CDCl3): 13.6, C4′; 16.7, C3′; 44.4, C2′; 99.3, 5-CHBr; 125.7, C4; 138.1, C3; 150.4, C5; 163.5, CO; 194.1, C1′. Mass spectrum: m/z 326, (M (81Br2), <5%); 324 (M (81Br, 79Br), 5); 320, (M (79Br2), <5); 298 (10); 296 (22); 281 (16); 279 (8): 225 (4); 131 (14); 77 (32); 71 (52), 43 (100).

Workup

  1. customprepared
  2. customAfter the completion of the reaction
  3. extractionextracted with ether (3×100 ml)
  4. washThe combined ether extracts were washed with brine (100 ml)
  5. dry with materialdried over sodium sulfate
  6. customevaporated
  7. customto yield the crude ketone (2.23 g, 81%) as a yellow solid
  8. customRecrystallisation of the crude ketone from dichloromethane/hexane

Sources & evidence

ORD record
ord-525813e83ed641cc93d0a3172b40995c
Source dataset
uspto-grants-2006_06
Patent number
US07064220B1

Reaction notes

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