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D E PA RT M E N T O F C H E M I S T RY CHEM 286L – Organic Chemistry Laboratory II Synthesis of Sulcatol (Part 2) Introduction Sodium borohydride reduction is a convenient way to synthesize alcohols from aldehydes or ketones. If the ketone starting material is unsymmetrically substituted, the resulting alcohol will be chiral. However, as the carbonyl group is planar, the reducing agent can transfer the hydride ion as easily from the top of the molecule as from the bottom and a racemic mixture is produced. TLC can easily check the progress of the reduction, as the alcohol product generally has smaller Rf values that the ketone starting material. Chemical The 6-methyl-5-hepten-2-one was reduced to the corresponding alcohol (sulcatol) previously and the reaction crude product will be purified by distillation in the second part of the experiment. O OH 1. NaBH4 2. H+, H2O Procedure Distillation of Sulcatol: Pay close attention to the distillation Set-up shown in the lab. Try to reproduce it as accurately as possible. Using a pipette, transfer your sulcatol (Crude) into a 10 mL round bottom flask, add a stir bar, and Step 1 attach it to your set-up. Start your water aspirator, and carefully “bubble off” the traces of ether present in the flask (Pay attention to the Instructor Demo). Once all the ether was removed, start your distillation by turning the heat up. Collect your distilled sulcatol in your Hickman’s head, and using a pipette, transfer it into a previously tarred clean 1-dram vial. Step 2 Take an IR of your final compound. IMPORTANT: during the distillation make sure to carefully report in your lab notebook the distillation temperature along with the distillation pressure.
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