Secondary Alcohol is converted into corresponding Cyanohydrin in two steps;
Step 1:
Oxidation of Sec. Alcohol:
Secondary Alcohols when treated with Sodium Dichromate in acidic medium are converted into corresponding Ketone.
Step 2:
Reduction of Ketone using HCN:
Ketone is reduced to Cyaynohydrin when treated with CN nucleophile. A nucleophillic addition reaction takes place.