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The synthesis of long chains of alkynes can be done by using acetylene as a starting material. The alkyl halides are also used for the elongation of the hydrocarbon chain.

The acetylide ion is made by the reaction of acetylide with a strong reducing agent such as NaH. NaH is a powerful reducing agent and is used for deprotonation in organic synthesis.

The synthesis of ethers can be done by the reaction of the alkoxide ions with the alkyl halides. The alkoxide ions have the general formula R-O^-

The acetylide ion then reacts with the alkyl halide to produce

${\mathrm{CH}}_3{\left({\mathrm{CH}}_2\right)}_5-\mathrm{C}≡\mathrm{C}-{\mathrm{CH}}_3$in the following reactions:

$$\begin{gathered} \mathrm{HC}≡\mathrm{CH}\stackrel{\mathrm{NaH}}{→}\mathrm{CH}≡{\mathrm{C}}^{-} \\ \mathrm{CH}≡{\mathrm{C}}^{-}+{\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Br}→{\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{C}≡\mathrm{CH} \end{gathered}$$

Synthesis of compound a

The product of the above reaction is then treated with the base NaH and epoxide to form the desired product.

$$\begin{gathered} {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Br}+\mathrm{HC}≡{\mathrm{C}}^{-}→{\mathrm{CH}}_3{\left({\mathrm{CH}}_2\right)}_5-\mathrm{C}≡\mathrm{CH} \\ {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2-\mathrm{C}≡\mathrm{CH}+\mathrm{NaH}→{\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2-\mathrm{C}≡{\mathrm{C}}^{-} \end{gathered}$$

Synthesis of the compound b