ACS Practice Final

Added: 2026-05-17

[00:00:00]Which reagents will convert one hexyne into two hexanone?

[00:00:07]First thing, draw these out.

[00:00:09]I know that this is going to have a triple bond at carbon one, and since this is hex, that's going to be six carbons.

[00:00:16]So, I'm just going to draw this in a linear way. I'm actually going to start off with the triple bond.

[00:00:22]And then I know that this is carbon one and two, and then I'll continue on with the rest of the carbon chain.

[00:00:27]So, I already have one and two, three, four, five, and six. I'll number this.

[00:00:34]Triple bond's at carbon one. This is two, three, four, five, and six. Great, that checks out. We're trying to convert this to a ketone.

[00:00:44]Where again, I do have six carbons. And then at carbon two, I have that carbonyl.

[00:00:51]Double check we do this correctly, where there's one, two, three, four, five, and six carbons.

[00:00:57]Now, we'll go down to our answer choices.

[00:01:00]What allows us to convert an alkyne into a ketone?

[00:01:06]Well, looking at the first one, this is actually another way to draw out the hydroboration oxidation reaction.

[00:01:15]Where this actually follows anti-Markovnikov's rule.

[00:01:18]So, it would create an aldehyde, not a ketone.

[00:01:23]That's out.

[00:01:26]If I looked at C, that's ozonolysis.

[00:01:28]That's going to actually give you two products. No, that's not what I'm looking for.

[00:01:33]D doesn't make sense because that's a Grignard reagent. All that does is we add an additional carbon. So, we add this methyl group, and we didn't change the amount of carbons. That's not our option, either. It had to be B.

[00:01:48]Remember what type of reaction this is.

[00:01:51]It's a type of hydration reaction that does follow Markovnikov's rule.

[00:01:55]Where if we start off with an alkyne, we're going to end up with a ketone.

[00:02:00]So, our answer for sure was B.