C6H5−CH=CHCHO⟶(X)C6H5CH=CHCH2OH
In the above sequence (X) can be:
H2 / Ni
NaBH4
HI/ red phosphorus
LiAlH4
Ph−CH=CH−CHO⟶NaBH4Ph−CH=CH−CH2OH
NaBH4 does not reduce (C=C) and (C≡C) bonds.