Experiment 1-Borohydride Reduction of Camphor PDF

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ochem 2 lab report on experiment 1...

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The Borohydride Reduction of Camphor Results: In this experiment, 1.026 grams of camphor and 1.039 g of sodium borohydride (NaBH4) were used. The mass of the final isoborneol product retrieved was 0.015 grams. The percent yield was calculated by dividing the actual yield by the theoretical yield and multiplying by 100. The percent yield is calculated below. Percent Yield=

0.015 grams final product Actual Yield ∗100= ∗100=1.46 % Theoretical Yield 1.026 grams camphor

The melting point determined for the isoborneol product was between 211.2oC and 214.4 C. When analyzing the NMR results of the final product, it was determined that the borneol chemical shift was measured at about 4 ppm with an integration of 1.00. The isoborneol chemical shift was at about 3.61 ppm with an integration of 2.25. The calculations for the percent of borneol and percent of isoborneol in the final product are shown below. o

1 integration of borneol ∗100= ∗100=30.8 % borneol 1+ 2.25 ∑ of integrations of borneol∧isoborneol 2.25 Percent of Isoborneol= ∗100=69.2% isoborneol 1+2.25 Percent of Borneol=

The IR spectra showed a slightly wide but short peak at 3326.3 cm-1 which indicates an alcohol group. The two peaks at 2949.05 cm-1 and 2874.51 cm-1 indicate two sp3-CH groups. The small peak at 1737.33 cm-1 indicates the presence of remaining camphor in the final product. From the IR spectrum peaks, it can be confirmed that the final product is isoborneol. Discussion: The reaction performed in this experiment was a borohydride reduction reaction. Sodium borohydride (NaBH4) is used instead of lithium aluminum hydride (LiAlH4) because it is a less reactive reducing agent. It is only strong enough to reduce aldehydes and ketones to alcohols. LiAlH4 reacts strongly with water which is not wanted for this experiment, therefore NaBH4 is preferred. In this borohydride reduction, camphor is reduced to form two products, the minor/endo product borneol and the major/exo product isoborneol. An exo and endo product are the results of this reaction as the carbonyl group in camphor is sp2 hybridized and the addition of hydride can occur at either face. Sources of Error: A possible source of error for this experiment could be incompletion of the reaction. This can be observed by the remains of camphor detected from the carbonyl group peak on the IR spectrum. Another possible source of error includes the solvent not being hot enough when dissolving the initial compound. If the solvent is not hot enough, not all impurities will be removed. Lastly, a possible source of error could be contamination of glassware if not cleaned properly. This could skew IR and NMR results and result in impurities and incorrect calculations. Conclusion:

The identified IR peaks at 3326.3 cm-1, 2949.05 cm-1, and 2874.51 cm-1 indicating the alcohol group and sp3-CH groups, NMR values, and melting point value between 211.2oC and 214.4oC successfully confirmed that the final product was isoborneol. The percent yield of 1.46% indicates that product was recovered, although, only a small amount. The percent of borneol (30.8%) and percent of isoborneol (60.2%) indicate the amount of each compound in the final product. From the data and observations, it can be concluded that the experiment successfully achieved the objective of conducting a borohydride reduction and observing the reaction changes and findings....