10,12-Docosadiynedioic acid → HCID 11279883, compound

HRID 2305246Notes

Reaction equation

HRID 2305246 reaction equation
[CH2:1]([C:24]([OH:26])=[O:25])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][C:9]#[C:10][C:11]#[C:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][C:21]([OH:23])=O.[CH3:27][Li]>C1COCC1.CCOCC>[O:23]=[C:21]([CH3:27])[CH2:20][CH2:19][CH2:18][CH2:17][CH2:16][CH2:15][CH2:14][CH2:13][C:12]#[C:11][C:10]#[C:9][CH2:8][CH2:7][CH2:6][CH2:5][CH2:4][CH2:3][CH2:2][CH2:1][C:24]([OH:26])=[O:25]

Participants

5

Reactant 2

HCID 54413810,12-Docosadiynedioic acidHCID 178418348HCID 178418348, compound2×

Product 1

HCID 11279883HCID 11279883, compound

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

1.08 g (3mmol) Icosa-9,11-diyne-1,20-dicarboxylic acid was suspended in 55 mL anhydrous THF and dissolved with slight warming. To this solution, 11.2 mL, 1.4 M methyl lithium in ether (8 mmol) was slowly added with the aid of syringe. A total of 2 mol equivalent of methyl lithium in ether were used per carboxylic acid to convert acid into ketone. The reaction turned into a viscous slurry from a free flowing suspension. The reaction was left stirring at room temperature overnight. The purplish colored suspension was treated with ice to quench the reaction. The product was extracted with ether, after acidifying the solution. The yellowish waxy product was characterized by NMR and found to contain the desired product as well as one byproduct tertiary alcohol due to additional reaction of methyl lithium present in the reaction mixture at the time of quenching. This problem was alleviated by addition of trimethyl silyl chloride in an amount enough to react with excess methyl lithium. This step provided clean reaction product.

Workup

  1. dissolutiondissolved with slight warming
  2. waitThe reaction was left
  3. additionThe purplish colored suspension was treated with ice
  4. customto quench
  5. customthe reaction
  6. extractionThe product was extracted with ether
  7. customto additional reaction of methyl lithium present in the reaction mixture at the time
  8. customof quenching
  9. additionThis problem was alleviated by addition of trimethyl silyl chloride in an amount enough
  10. customto react with excess methyl lithium
  11. customThis step provided clean reaction product

Sources & evidence

ORD record
ord-84edb668f7454a52b40cf2a71c246682
Source dataset
uspto-grants-2002_08
Patent number
US06440056B1

Reaction notes

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