Hexynes deprotonation

Pale and coworkers have demonstrated that silver acetylides may be synthesized with a variety of silver salts in the presence of base in a number of solvents. By treating 1 -hexyne in either deuterated benzene or DMF with silver triflate, the group was able to observe the formation of the Jt-alkyne-silver complex and subsequently the silver acetylide through the use of H, C, and Ag NMR. The incipient Jt-alkyne-silver complex is rapidly deprotonated on addition of diisopropylethylamine, to give the silver acetylide as a white precipitate (Scheme 1.33).89... 

Now, let s draw the forward scheme. Radical bromination of 2-methylbutane produces the tertiary alkyl hahde, selectively. Then, elimination with NaOEt, followed by awti-Markovnikov addition (HBr / peroxides), and then elimination with iert-butoxide, followed by another awri-Markovnikov addition (HBr / peroxides) produces l-bromo-3-methylbutane. This alkyl hahde will then undergo an Sn2 reaction when treated with an acetylide ion to give 5-methyl-1-hexyne. Ozonolysis of this terminal alkyne cleaves the CC triple bond, producing the carboxylic acid. Deprotonation (with NaOH) produces a carboxylate nucleophile that subsequently reacts with bromomethane in an Sn2 reaction to give the desired ester. 

Hexyne is made from an S]m2 reaction between acetylene (which must be deprotonated to form an acetyhde ion) and 1-bromobutane. 

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