We have computed new stellar evolution models that include the effects of rotation and magnetic torques under different hypothesis .
The goal is to test if a single star can sustain in the envelope the rotational velocities needed for the magneto hydrodynamical ( MHD ) simulations to shape bipolar Planetary Nebulae ( PNe ) when the high mass-loss rates take place .
Stellar evolution models with main sequence masses of 2.5 and 5 M _ { \odot } , and initial rotational velocities of 250 km s ^ { -1 } have been followed all the way to the PNe formation phase .
We find that stellar cores have to be spun down using magnetic torques in order to reproduce the rotation rates observed for white dwarfs .
During the asymptotic giant branch phase and beyond , the magnetic braking of the core has a practically null effect in increasing the rotational velocity of the envelope since the stellar angular momentum is removed efficiently by the wind .
We have , as well , tested best possible case scenarios in rather non-physical contexts to give enough angular momentum to the envelope .
We find that we can not get the envelope of a single star rotating at the speeds needed by the MHD simulations to form bipolar PNe .
We conclude that single stellar rotators are unlikely to be the progenitors of bipolar PNe under the current MHD model paradigm .