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54B EXPERIMENT 54B: Synthesis of B-Benzopinacolone: The Acid-Catalyzed Rearrangement of Benzopinacol
The ability of Carbocations to rearrange represents an important concept in Organic chemistry. In this experiment, the benzopinacol prepared in Experiment 5-OTG will rearrange to benzopinacolone (2,2,2-triphenylacetophenone) under the influence of iodine in glacial acetic acid.
OH
glacial acetic acid
H2O
The product is isolated as a crystalline white solid. Benzopinacolone is known to crystallize in two different crystalline forms, each with a different melting point. The alpha form has a melting point of 206°C-207°C, whereas the beta form melts at 182°C. The product formed in this experiment is the B-benzopinacolone:
OH