[emmazola]

Hi all,
I am currently writing my report and had to answer the question: The alkyne was chosen as the hydroxy isopropyl group can be easily removed, as shown in the scheme below, permitting further coupling reactions to take place. Draw a mechanism to show how this might occur, take into account the pKa of an alkyne.
I was unsure on the mechanism for this so drafted one up in ChemDraw, could anyone please look over this and comment on its validity? Many thanks!

[Babcock_Hall]

I see a number of things that strike me as debatable.  The one that jumped out was that you have a hydride ion attacking an electron-rich position near the end of the mechanism.

[rolnor]

I dont understand, Is the alkyne a protecting group? What is it protecting?

[rolnor]

As the first step, you just pick the proton from the hydroxyl group, forming a alkoholate and hydrogen gas.

[dianereese]

I dont understand, Is the alkyne a protecting group? What is it protecting?sprunki retake

The base abstracts a proton from the newly exposed terminal alkyne (due to its moderately acidic nature, pKa ~25), ensuring the formation of the deprotected terminal alkyne and water or an alcohol as the byproduct.