" A Wittig reaction with an aldehyde gives "

Oxidation of aldehydes gives

What is wittig reaction?

Reaction OF aldehyde

Ketones give nucleophilic addition reactions more readily than aldehydes.

NA (nucleophilic addition) reaction of alcohols with aldehydes gives hemiacetal, whereas phenols react with aldehydes and ketones in acidic medium and give electrophilic substitution product (I) , which further reacts with phenol to give (II) , Explain.