You cannot match this directly, because the data is not there anymore (when the request is send to the server we don’t keep a copy of it).
I suggest you save the path to a txn variable in the frontend and than use that in the backend:
frontend ...
http-request set-var(txn.path) path
backend ...
acl path_set var(txn.path) -m beg /some/path
http-response del-header Pragma if path_set
http-response set-header Cache-Control no-cache if path_set
http-response set-header Expires -1 if path_set
See the documentation for details: