What can Deprotonate an alkyne?

If you treat a “terminal alkyne” (an alkyne that ends in a C-H bond) with a strong base such as NaNH2, it will be deprotonated to form its conjugate base – called an “acetylide”.

What is the reactivity of alkyne?

The extra π linkage (alkynes have two π bonds) makes the triple bond even more reactive. Thus, alkynes are very reactive, and with the exception of ethyne, commonly referred to as acetylene (C2H2), they are not commonly encountered.

What is the product of the hydrogenation of an alkyne?

Mechanism of the Hydrogenation When an alkyne is hydrogenated with Lindlar’s catalyst, we get an alkene. What’s important to realize is that we always get an alkene in which the hydrogen atoms are on the same side of the carbon-carbon double bond.

How many products will hydration of the alkyne produce?

The hydroboration of symmetrical alkynes produces one ketone product and asymmetrical alkynes produce a mixture of product ketones.

Are alkynes basic?

1-Alkynes are very weak acids, hence their conjugate bases, RC≡C⊖, are quite strong bases. These anions also are reactive carbon nucleophiles, and it is this property that makes them useful for organic synthesis.

Why are alkynes less reactive than alkenes?

Alkynes are usually less reactive than alkenes in electrophilic addition reactions because the π electrons are “held” more tightly in C≡C bonds then in C=C bonds. It is also more sterically difficult to form a bromonium ion from an alkyne (Figure 10.29) than from an alkene.

What alkyne is most reactive?

The reactivity is: Alkynes > Alkenes > Alkanes. Alkynes have two pi-bonds between two (or more) carbon atoms, along with a sp-sp hybridised orbital bonding (sigma bond).

What is hydration of alkyne?

Hydration of alkynes begins similar to the hydration of alkenes through the addition of the first water molecule. As with alkenes, hydration (addition of water) to alkynes requires a strong acid, usually sulfuric acid with a mercuric sulfate catalyst as shown below.

What type of compound is formed from the hydration of an alkyne?

Hydration of Terminal Alkyne produces methyl ketones Just as described in Figure 7 the π electrons will attack a proton, forming a carbocation, which then gets attacked by the nucleophilic water molecules. After deprotination, we generate an enol, which then tautomerizes into the ketone form shown.