What follows is a brief description of the procedure by which my lab partner and I just synthesized via a Stork enamine reaction as a precursor to the queen bee pheromone, (2E)-9-oxo-2-decenoic acid. I'm aware that there are many chemists on E2, many of whom could think of a better way to do this, but this is how we did it. I am omitting exact amounts, because 1) our yield was rather embarrassing, and 2) the procedure should scale up or down reasonably well.
1. Stoichiometric equivalents of cyclohexanone and piperidine were dissolved in dry toluene with a catalytic amount of p-toluenesulfonic acid in a round-bottom flask.
2. A reflux condenser was attached, along with a drying tube packed with silica, and the mixture was refluxed for approximately 45 minutes.
3. Distillation apparatus was attached, and the mixture was distilled until approximately 40% of the water-toluene mixture was removed.
4. A stoichiometric equivalent of acetic anhydride was added, and the mixture was refluxed again for another 45 minutes.
5. Deionized water was added, and the mixture is refluxed for another 45 minutes.
6. The mixture was transferred to a separatory funnel, where it was combined with a roughly equivalent volume of deionized water, and the aqueous layer discarded.
7. A roughly equivalent volume of 6M HCl was added, and the aqueous layer discarded as above.
8. The remaining organic layer was subjected to vacuum distillation at approximately 40 torr, up to approximately 120 degrees celcius, which served to remove the water, the toluene, and the majority of other liquid impurities.
9. TLC was performed on the raw product, which indicated the presence of the desired product (and its tautomer) in addition to some amount of piperidine and cyclohexanone (and its tautomer).
10. The product was separated via column chromatography, using 10% EtOAC by volume in hexanes.