How do you convert Benzaldehyde to Benzophenone in exactly two steps?
You do a Grignard reaction followed by an oxidation.
Step 1: benzaldehyde + phenylmagnesium bromide → diphenylmethanol
Step 2: diphenylmethanol + chromyl chloride → benzophenone
You can use any reagent that converts a secondary alcohol to a ketone.
These include acidified potassium dichromate, pyridinium chlorochromate, and chromyl chloride.