p-Toluenesulfonic acid → HCID 131715943, compound

Participants

Reaction Steps

To a solution of 2.4 g of cis-2-bromo-ethoxyethylene in 75 ml of THF at -78°, was added dropwise 2.0 g of t-butyllithium (2.2 m in pentane). After stirring at -78° for 2 hours, a solution of 3.5 g of the aldehyde product of Step 2, above, in 30 ml of THF was added dropwise. The reaction was stirred at -78° for 10 minutes, then was quenched by the addition of saturated aq. ammonium chloride solution. The mixture was extracted once with MTBE and then once with methylene chloride. The organic solutions were combined, dried over anhyd. magnesium sulfate and concentrated under reduced pressure to obtain a residue. The residue was dissolved in 100 ml of THF/water (90:10). p-toluenesulfonic acid (0.7 g) was added and then the mixture was stirred at room temperature for 1 hour. The reaction mixture was poured into 10% aq. sodium bicarbonate solution and the organic material was extracted with MTBE. The solution was dried and the solvent removed under reduced pressure to give 3.7 g (98% yield) of the title product of this step for use in the next step (4). An analytical sample was crystallized from hexane; m.p. 138°-140°;

Provenance & Evidence