During aldol condensation - OH group appears at:

Explanation

During aldol condensation, the -OH group appears at the beta-carbon position. Let me explain what that means.In aldol condensation, two molecules of carbonyl compounds, such as aldehydes or ketones, come together and undergo a reaction. One molecule acts as the nucleophile and donates an enolate ion, which is a carbon-carbon double bond with a negative charge. The other molecule acts as the electrophile and accepts the enolate ion.Now, the beta-carbon refers to the carbon atom adjacent to the carbonyl carbon. When the enolate ion attacks the electrophile, it forms a new carbon-carbon bond. As a result, the -OH group is attached to the beta-carbon, which is the carbon atom next to the carbonyl carbon.This addition of the -OH group at the beta-carbon is a key characteristic of aldol condensation reactions. It's pretty cool how these reactions can lead to the formation of new carbon-carbon bonds and the introduction of functional groups like -OH.