Does Phenol react with CrO 4 2- and if so, whatis the rxn equation?..and does Cy

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Explanation / Answer

Potassium or sodium dichromate (K2Cr2O4 or Na2Cr2O4) formdichromate (Cr2O4)2- which is a reasonably strong oxidizingreagent. When dichromate oxidizes something it is itself reduced. Dichromate oxidizes primary alcohols into aldehydes initially, andeventually to carboxylic acids. Dichromate oxidizes secondary alcohols in to ketonesreadily. 1. (CrO4)2- pulls the alcohol's proton off leavingC6H5O-. 2. (HCrO4)- pulls a proton off the carbon attached to the O-creating a secondary carbocation attached to a negatively chargedoxygen. 3. Lone electron pair on the oxygen attaches to thepositively charged carbon simultaneously completing the oxygen andcarbon's octet. So cyclohexanol + dichromate + H+ -----> cyclohexanone +H2Cr2O4(acidic dichromate) via a [C6H5-O---H---Cr2O4] intermediate. **In regards to the dichromate reaction with phenol, oxidationoccurs but the result is more complex: 1. Cr2O4 deprotonates the -OH group on the phenol. 2. Resonance stabilizes the negatively charged intermediate.(4 forms) 3. The negative charge on the ring grabs a proton from eitheran acid or back from HCr2O4. 4. End result is cyclo-2,5-dienehexanone, or somethingsimiliar.

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