I´ve used the paste as plain text from a word document and all looks fine in the editor in the backend. However, when saved all the apostrophes appear as an accent on the character previous to the apostrophe in the front end .

It looks like you are not using an apostophe in the original document, but rather the acute symbol, which is why the pasted text contains this instead of apostrophe.

I notice too that you have used the same symbol in the I´ve of your post text, which should be written as I've with an apostrophe.