  Assuming a type-I seesaw mechanism for neutrino mass generation and invoking
a baryogengesis via leptogenesis scenario, we consider a reasonable
hierarchical structure for Dirac neutrino mass matrix, similar to up-type quark
mass matrix. These hypotheses imply a relevant connection between high scale CP
violation and low energy one. By requiring a compact heavy neutrino mass
spectrum, which allows to circumvent Davidson-Ibarra limit, one can obtain an
efficient leptogenesis restricting the allowed region for low energy neutrino
parameters. Once the oscillating parameters are taken inside a $3\sigma$ range,
through the numerical resolution of the leptogenesis Boltzmann equations one
gets the following allowed intervals for the lightest neutrino mass and the
Dirac CP phase: $-0.90\pi<\delta<-0.75\pi$ and $m_1\sim( 0.002 - 0.004)$ eV.
