Conversion of key files to doc file format

Probably not very common, but you could copy paste the text from a Keynote presentation (.key) and save it in Word document format (.doc) using your preferred word processor, which will essentially achieve key to doc conversion for you. Or you might print the Keynote to PDF and open it in Word to preserve some of its formatting. At any rate, these two formats are not that compatible, nevertheless some kind of export is possible.

Open KEY file    Open DOC file