Design syntheses of compounds i , i and iii using the pool of carbon-containing starting materials given in the box below and any synthetic

Answer

Organic Synthesis of Compounds i, ii, and iii

🔹 Compound i: Tri-substituted Ether

Strategy: Synthesize via multistep Williamson ether synthesis using the alkoxides of benzyl alcohol and cyclohexylmethanol.

1. Convert benzyl bromide to benzyl alcohol via SN2 with NaOH. Then deprotonate with NaH → benzyl alkoxide.
2. React with 1 equivalent of 1,3-dibromopropane → intermediate mono-ether (with remaining Br).
3. Convert cyclohexylmethyl bromide to cyclohexylmethanol → deprotonate to form alkoxide.
4. React second alkoxide with mono-substituted intermediate → final tri-substituted ether.

🔹 Compound ii: Ethyl Benzoate (Ester)

Strategy: Oxidize benzyl bromide to benzoic acid and perform Fischer esterification with ethanol.

1. Oxidize benzyl bromide with KMnO₄ → benzoic acid.
2. React benzoic acid with ethanol in H⁺/heat → ethyl benzoate.
3. Ethanol can be assumed available or derived from reduction/cleavage of suitable diol intermediates.

🔹 Compound iii: Epoxide with Phenethyl and Butyl Side Chains

Strategy: Build a substituted alkene, then oxidize it to the epoxide.

1. React benzyl bromide with deprotonated acetylene (NaNH₂) → phenyl-propyne.
2. Partial hydrogenation (Lindlar’s catalyst) → cis-alkene.
3. Alkylate with 1-bromobutane or equivalent → 1-phenyl-1-butene.
4. Epoxidize using mCPBA or peracid → substituted epoxide (as shown).

🧾 Summary Table: