Compound P (CX7HX6O) on refluxing with aqueous ethanolic KCN solution for 1 hour, forms Q (CX14HX12OX2). Q on oxidation gives R (CX14HX10OX2). R on refluxing with aqueous NaOH solution followed with acidification forms an α−hydroxyacid S (CX14HX12OX3). What are the structures of the compounds?
My effort:
P has DBE (double bond equivalent) equal to 8, so 2 benzene rings (not possible with 7 carbons) or some cyclic or many double bonds might be necessary. Now some enolate reaction might be happening with KCN, like aldol or Perkin or Knoevnagel or Stobbe or Claisen or benzoin etc. Oxidation doesn't affect the formula so it might be becoming an isomer (that too a functional one). After that a Cannizaro might be the thing.