The chemical reduction of 1,3-butadiene with sodium in alcohol gives mainly the 1,4-addition product that is but-2-ene. Under these condition the isolated double bond are not reduced. This suggest that dienes are much more reactive than simple alkenes.
Why is diene more reactive than alkene even though the conjugated double bond of diene (in the example of excerpts given above) is stabilized with resonance? How is 1,4-addition product the major product?