  Motivated by applications to black hole physics and duality, we study the
effect of higher derivative corrections on the dimensional reduction of
four-dimensional Einstein, Einstein Liouville and Einstein-Maxwell gravity to
one direction, as appropriate for stationary, spherically symmetric solutions.
We construct a field redefinition scheme such that the one-dimensional
Lagrangian is corrected only by powers of first derivatives of the fields,
eliminating spurious modes and providing a suitable starting point for
quantization. We show that the Ehlers symmetry, broken by the leading $R^2$
corrections in Einstein-Liouville gravity, can be restored by including
contributions of Taub-NUT instantons. Finally, we give a preliminary discussion
of the duality between higher-derivative F-term corrections on the vector and
hypermultiplet branches in N=2 supergravity in four dimensions.
