Lithium aluminum hydride (LiAlH4) was not used as a reducing agent because it reacts too violently with the benzoin. For this experiment, changing the reducing agent from NaBH4 to LiAlH4 would not have caused an increase in the amount of conserved product. The use of NaBH4 showed that benzoin was completely reduced. Spot (C) on the TLC plates shows that there is a separation between the starting material and the product, therefore the starting material is not the same as the product. A more polar product is shown due to the differences in the Rf values, which confirms that the product is 1,2-diphenylethane-1,2 diol because the mechanism shows that the starting material is less polar than the product. After the benzoin is reduced, the hydrochloric acid protonated the oxygen ion. Adding more hydrochloric acid to the solution could make it so that the oxygen ion is more efficiently pronated, which would yield a higher product yield.
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