  The origin of hard X-rays and gamma-rays emitted from the solar atmosphere
during occulted solar flares is still debated. The hard X-ray emissions could
come from flaring loop tops rising above the limb or Coronal Mass Ejections
(CME) shock waves, two by-products of energetic solar storms. For the shock
scenario to work, accelerated particles must be released on magnetic field
lines rooted on the visible disk and precipitate. We present a new Monte Carlo
code that computes particle acceleration at shocks propagating along large
coronal magnetic loops. A first implementation of the model is carried out for
the 2014 September 1 event and the modeled electron spectra are compared with
those inferred from Fermi Gamma-ray Burst Monitor (GBM) measurements. When
particle diffusion processes are invoked our model can reproduce the hard
electron spectra measured by GBM nearly ten minutes after the estimated on-disk
hard X-rays appear to have ceased from the flare site.
