Note that these types of questions are often the most difficult on the examination. This is because they are holistic in that they require a good understanding of the reactions and the concepts and the ability to apply those concepts from the course as a whole. They can't be memorised, they require understanding and ability to apply. Hence they help discriminate those who truly understand from those who have memorised and will soon forget.

Structures...

Reactions involved:

A to B + C = ester hydride reduction gives two alcohols

A to D = ester enolate alkylation

D to E + C = ester hydrolysis gives carboxylic acid + alcohol

E to F = carboxylic acid reduction to a primary alcohol

C to G = oxidation to ketone (based on FG tests)

G to H = Wittig reaction

H to I = hydroboration / oxidation to anti-Markovnikov alcohol

I to J = oxidation to aldehyde or ketone

J to A = Baeyer-Villager ketone to ester