Question: Show how you would synthesize the following carboxylic acids, using the indicated starting materials.

(a) $\mathbf{hex}\mathbf{-}\mathbf{3}\mathbf{-}\mathbf{yne}\to \mathbf{propanoic}\mathbf{acid}$

(b) $\mathbf{cis}\mathbf{-}\mathbf{cyclodecene}\to \mathbf{decanedioic}\mathbf{acid}$

(c ) $\mathbf{iodobenzene}\to \mathbf{phenylacetic}\mathbf{acid}$

(d)$\mathbf{pentan}\mathbf{-}\mathbf{3}\mathbf{-}\mathbf{ol}\to \mathbf{2}\mathbf{-}\mathbf{ethylbutanoic}\mathbf{acid}$

(e)$\mathbf{o}\mathbf{-}\mathbf{xylene}\to \mathbf{phthalic}\mathbf{acid}$

(f) $\mathbf{allyl}\mathbf{bromide}\to \mathbf{but}\mathbf{-}\mathbf{3}\mathbf{-}\mathbf{enoic}\mathbf{acid}$

(a) When hex-3-yne is treated with concentrated ${\text{KMnO}}_{\text{4}}$or${\text{O}}_{\text{3}}{\text{/H}}_{\text{2}}\text{O}$, alkyne is oxidized to propanoic acid.

(c) It forms a Grignard reagent when iodobenzene is treated with Mg in an ether solvent. Further, on treating with oxirane and heating with an acid, primary alcohol is formed. At last, in excess of NaOCl, alcohol is converted to phenylacetic

acid.

(d) When pentan-3-ol is treated with ${\text{PBr}}_{\text{3}}$, it forms 3-bromopentane. Further, on treating with Mg in the presence of an ether solvent and then with carbon dioxide, and at last on heating with an acid, it converts into 2-ethylbutanoic acid.

(f) When allyl bromide is treated with Mg in the presence of an ether solvent and further treated with carbon dioxide, and at last, when treated with acid, it forms but-3-enoic acid.