Hydroboration then oxidation with carbon monoxide and hydrogen peroxide

[![given question](https://i.stack.imgur.com/ZGCNw.jpg)](https://i.stack.imgur.com/ZGCNw.jpg)


Thus is the question given in my textbook


[![my working](https://i.stack.imgur.com/l3GJl.jpg)](https://i.stack.imgur.com/l3GJl.jpg)
This is my attempt at the question [![given solution](https://i.stack.imgur.com/R6qmZ.jpg)](https://i.stack.imgur.com/R6qmZ.jpg)


This is the solution given in the textbook.


I don't understand how a ketone is formed instead of an acid. [related question](https://chemistry.stackexchange.com/questions/96262/hydroboration-oxidation-reaction-on-trans-trans-trans-1-5-9-cyclododecatriene-wi) This is a related question but in this a tertiary alcohol is formed instead of a ketone. What is the mechanism of formation if ketone and why is my mechanism wrong?




There is a good explanation of the possible mechanisms of the ketone formation  [here](https://www.ch.ic.ac.uk/local/organic/tutorial/rzepa13/) which I have reproduced below. No pathway leads to an acid. Your mechanism has multiple CO insertions and only one occurs.


[![enter image description here](https://i.stack.imgur.com/ThRsZ.gif)](https://i.stack.imgur.com/ThRsZ.gif)


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