Carlos Caceres Chemistry 3B lab The Wittig Reaction Purpose: To use the Wittig reaction to produce an oxide and an alkene. Data: 173 mg Methyl Acetate added 76 mg Nitrobenzaldehyde Added- Yellow crystals 100mg silica gel added- white powder After the microwave, product had turned into a caramel color, powdery mixture. Theoretical Yield: 173 Mg Percent Yield: 57.97% Melting Point: 49.3-52.4 ° C Discussion: The 2 alkene isomers formed in the reaction are E and Z isomers. By looking at the NMR spectra of the product, you can see that there are smaller peaks with smaller integration values. This shows that although both isomers were produced, one was made in greater quantities. By simply looking at the 2 structures of the products, I can assume that the E alkene was produced because it has less steric hindrance than the Z alkene.
By performing the reaction in silica gel, you can ensure a better mixing between the product and the silica gel, resulting in better separation between the formed products. This results in better separation between the mixed products.
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