a) What would be the product formed if diphenylacetylene were reacted with aqueous sulfuric acid?
b) What would be the product formed if diphenylacetylene were reacted with two equivalents of HBR?
a) To determine the product formed when diphenylacetylene reacts with aqueous sulfuric acid, we need to consider the reaction between the compound and the acid. Diphenylacetylene is an alkyne compound, specifically a terminal alkyne, which means it has a triple bond at the end of the carbon chain.
When diphenylacetylene reacts with aqueous sulfuric acid, the sulfuric acid will act as a strong acid and protonate the alkyne. Protonation involves the addition of a proton (H+) to the alkyne, resulting in the formation of a carbocation intermediate.
The carbocation intermediate can undergo various reactions, such as rearrangements, but in this case, we can consider the addition of a water molecule (H2O) to the carbocation. This addition leads to the formation of an alcohol.
Therefore, the product formed when diphenylacetylene reacts with aqueous sulfuric acid would be an alcohol, specifically a phenol.
b) To determine the product formed when diphenylacetylene reacts with two equivalents of HBr (hydrogen bromide), we need to consider the reaction between the compound and the acid. Diphenylacetylene is an alkyne compound, specifically a terminal alkyne, which means it has a triple bond at the end of the carbon chain.
When diphenylacetylene reacts with two equivalents of HBr, an addition reaction occurs. The first equivalent of HBr will add across the triple bond, forming a new carbon-bromine bond and breaking the triple bond to create a vinyl bromide intermediate.
Then, the second equivalent of HBr will add across the remaining triple bond in the vinyl bromide intermediate, resulting in the addition of another bromine atom and breaking the triple bond completely.
As a result, the product formed when diphenylacetylene reacts with two equivalents of HBr would be 1,2-dibromo-1,2-diphenylethane.