Sorry Borek, I didn't know that. Now I do.
"orgopete"...Ch3 groups have an I+ effect, better than H. Ch3 will reduce the (+) local electron density of the C of de carbonilyc group makin' it less reactive to an NA.
Alifatic groups have an I- effect but a more powerful M+ effect by resonance.
the problem is that... I know that "c" is more reactive than "a". but i don't know if resonance effect is strong enough to surpass those methilic groups on... my guess is