Sometimes an organic synthesis involves using a particular functional group because of its unique reactivity and then removing this functional group later.
Consider the proposed transformation shown below.

Part 1: Start by identifying the carbon atoms in the product that most likely derive from the starting material. Be sure to identify carbon atoms, not bonds.

Part 2: Which of the following options correctly describes the reactivity of an α,β-unsaturated carbonyl system and the type of reagent required to increase the carbon chain length?
Choose one or more:
The reagent required is CH3CH2Li.
This system reacts primarily as a nucleophile.
The reagent required is (CH3CH2)2CuLi.
The reagent required is CH3CH2Br.
This system is electrophilic at the β carbon atom.

Part 3:Which synthetic steps could be used to complete this synthesis?
Choose one or more:
H2, Pt
Zn/Hg, HCl
i) LiAlH4, THF; ii) H3O+
NH2NH2, OH–, heat
NaBH4, CH3OH