10,12-Docosadiynedioic acid → HCID 11279883, compound

Participants

Reaction Steps

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.

Provenance & Evidence