Sure — but it is hazardous. The transmission of legal advice is usually from the attorney to a client, and there are ethical requirements surrounding it to protect the client. The issue would be, as to an uncomfortable number of transactions, was the CEO acting in that capacity (possibly no provilege if the transaction was for a business, not a provable legal purpose? Or was the transaction solely legal advice? Possible, but leaving an open door for a lot of later argument.
What if, during a meeting of a board of directors, the CEO then begins to discuss legal issues? Does that waive any privilege on the basis that it was business – not legal – advice? If part of each, was the privilege waived by comingling with the business side?
It would be enough of an argument to have a good chance of surviving a summary judgment motion, meaning requiring a trial. Not a horse I would want to put money on either way.