[rentj]

I was learning about ketones and aldehydes until I found this in the book. Isn't the third step supposed to be MCPBA or any peroxy acid? Thank you.

[rolnor]

You get an aldehyde from the ozonolysis, do you suggest that this can be oxidized to carboxylic acid with a peroy acid?

[Meter]

You get an aldehyde from the ozonolysis, do you suggest that this can be oxidized to carboxylic acid with a peroy acid?

Is Bayer Villager not plausible?

[rolnor]

That would give you an ester? From a ketone?

https://en.wikipedia.org/wiki/Baeyer%E2%80%93Villiger_oxidation#cite_note-named-1

[Meter]

That would give you an ester? From a ketone?

https://en.wikipedia.org/wiki/Baeyer%E2%80%93Villiger_oxidation#cite_note-named-1

Literature is shaky on this because no one in their right mind would oxidize benzaldehyde with BV to yield benzoic acid. Seems like the 'aldehyde' ester needs a bit more exotic reagents than just peroxyacids (Natu, A. D., Burde, A. S., Limaye, R. A., & Paradkar, M. V. (2014). Acceleration of the dakin reaction by trifluoroacetic acid. Journal of Chemical Research, 38(6), 381-382. doi:https://doi.org/10.3184/174751914X14014814873316). Didn't take time to read it thoroughly.

For the record OP, can you think of a way that step 2 could yield the final product?

[rolnor]

You can do it in just one step with permanganate, it's not a very good scheme