If the reaction were to be carried out with concentrated HClinstead of concentra
ID: 912135 • Letter: I
Question
If the reaction were to be carried out with concentrated HClinstead of concentrated H3PO4 with acatalytic amount of sulfuric acid, a mixture of two products wouldbe formed. After the two products were separated, one product wouldgive a positive test for unsaturation and the other product wouldgive a negative test for unsaturation. What would be the identitiesof the two products. The original reaction was cyclohexanol + Phosphoric acid -->cyclohexene + water. I know a positive saturation test means there is a double bond inthe product and a negative saturation test means there is no doublebond in the product. I'm just not certain about the productshere. Cyclohexanol + HCl ----------> ?
Explanation / Answer
If HCl is used instead of H3PO4 in the reaction, an SN1 reaction may occur to form chlorocyclohexane as the other product. I would predict this product would be formed as a minor one and the cyclohexene would remain as the major product of this reaction. So we have,
cyclohexanol + H2SO4 ---> Cyclohexene [unsaturated]
cyclohexanol + HCl -----> chlorocyclohexane [saturated]