  It has been recently proposed to study coherent deeply virtual Compton
scattering (DVCS) off 3He nuclei to access neutron generalized parton
distributions (GPDs). In particular, it has been shown that, in Impulse
Approximation (IA) and at low momentum transfer, the sum of the quark helicity
conserving GPDs of 3He, H and E, is dominated by the neutron contribution. This
peculiar result makes the 3He target very promising to access the neutron
information. We present here the IA calculation of the spin dependent GPD
tilde-H of 3He. Also for this quantity the neutron contribution is found to be
the dominant one, at low momentum transfer. The known forward limit of the IA
calculation of tilde-H, yielding the polarized parton distributions of 3He, is
correctly recovered. The extraction of the neutron information could be anyway
non trivial, so that a procedure, able to take into account the nuclear effects
encoded in the IA analysis, is proposed. These calculations, essential for the
evaluation of the coherent DVCS cross section asymmetries, which depend on the
GPDs H, E and tilde-H, represent a crucial step for planning possible
experiments at Jefferson Lab.
