Consider the following sequence of reactions, taken from the early steps in a synthesis of -fluorooleic acid,

Consider the following sequence of reactions, taken from the early steps in a synthesis of ω-fluorooleic acid, a toxic natural compound from an African shrub.

(ω-Fluorooleic acid, also called “ratsbane,” has been used to kill rats and also as an arrow poison in tribal warfare. Two more steps beyond those below are required to complete its synthesis.)

(i) 1-Bromo-8-fluorooctane + sodium acetylide (the sodium salt of ethyne) →compound A (C₁₀H₁₇F)

(ii) Compound A + NaNH₂ → compound B (C₁₀H₁₆FNa)

(iii) Compound B +I − (CH₂)₇−Cl → compound C (C₁₇H₃₀ClF)

(iv) Compound C + NaCN  compound D (C₁₈H₃₀NF)

(a) Elucidate the structures of compounds A, B, C, and D above.

(b) Write the mechanism for each of the reactions above.

(c) Write the structure of the transition state for each reaction.