Question

A cyanohydrins formation reaction of a ketone/aldchydc is often thought to be mechanistically analogous to base-catalysed hydration reaction. It is usually done in two steps. In the first step the ketone/aldehyde is mixed with a solution of sodium or potassium cyanide, which is followed by the addition of an acid, typically sulphuric acid. Please provide a mechanism for the following two-step procedure. (6') Can a cyanohydrin formation reaction occur at a reasonable rate under an acid-catalysed condition as shown below? You need to justify your answer.

Answer 1

OH Ht R" R" R" CN [c=EN]

2) Cyanohydrins have the structural formula of RCIOH)CN. The R on the formula represents an alkyl, aryl, or hydrogen. In orderto form a cyanohydrin, a hydrogen cyanide adds reversibly to the carbonyl group of an organic compound thus forming a hydroxyl-alkanenitrile adducts (commonly known and called as cyanohydrins). CH,-CH 2-CH,-CH 2-CHO + HCN