  A boundary-state computation is performed to obtain derivative corrections to
the Chern-Simons coupling between a p-brane and the RR gauge potential C(p-3).
We work to quadratic order in the gauge field strength F, but all orders in
derivatives. In a certain limit, which requires the presence of a constant
B-field background, it is found that these corrections neatly sum up into the
*2 product of (commutative) gauge fields. The result is in agreement with a
recent prediction using noncommutativity.
