  In this paper we study the dynamics of flavor transformation for neutrinos
propagating in the very dense environment of astrophysical compact objects as
Type II supernova in post collapse phase and proto-neutron stars. The analysis
is based on the generalized Boltzmann equation, which incorporates the
neutrinoneutrino interaction. We focus the analysis on the possible collective
flavor dynamics, which can displays bipolar and synchronized flavor
oscillations, and the associated transition from single-angle to multi-angle
regime. To solve the kinetic equations we use an expansion in Legendre
polynomials and a two-flavor scheme. On the basis of the numerical simulations
we argue that neutrino flavor dynamics is suppressed by the presence of the
electron component up to a certain distance from the neutrino sphere, where a
transition to multi-angle regime occurs. This distance will move towards the
neutrino sphere as the neutrino emission epoch proceeds.
