None of these is fantasy in the usual sense but anyway...

Andrew Greig, When They Lay Bare, a novel built around "The Twa Corbies".

Ian F. Benzie, The Year's Midnight, using the story of the execution of Macpherson.

Flann O'Brien, At Swim-Two-Birds, using the mediaeval Irish mostly-prose story of Mad King Sweeney.

Somebody or other recycling the Odyssey and setting it in early 20th century Dublin.