Show how you would accomplish the following transformations (each arrow may represent multiple reaction steps):
a) Benzene --> Acetophenone --> Styrene
b) Benzoic acid --> 1-phenyl-1-hexanone --> 3-phenyl-2-octene
c) Butanoic acid (CH3CH2CH2COOH) --> butanal --> 1-pentene --> 2-pentene --> acetaldehyde
d) Propanenitrile (CH3CH2CN) --> 2-butanone--> 3-methyl-3-pentanol