Sp hybridization

Pi electrons are cylindrical

Alpeen vs Alpine

Nucleophiles in these reactions

Specroscopy changed haw we viewed spectroscopy à mentioned the quiz so the students know what’s up

Induced local magnetic field of the pi electrons

For hydrogens, flow of pi electrons essentially defend the shielded     this is a lot holy shit

Alkynes “nomenclature” lol

Write out 5 methyllhept-1-yne and 3 methyllhept-1pen-6-yne

Student asks “is this alpine or Alpeen”

Teacher “forgot I even had this slide” just side talking to students

Student laughs

So when the director asks about nomenclature I can say yeah sure

Students are very intensely watching either the screen or Dr. Feducia.

Chairs squeak a lot. They are unsettled

Counting carbons is the most difficult part for students –Dr.f

Still a seven carbon chain and we look at this multiple bond

Enines, not niens

You’re not going to bed oingany thing really crazy

Student asks about structure, Feducia draws the structure out, there is only a linear structure,

Impossible for cis Alkynes – makes jokens about how you cant have trans

Students laugh. They seem to enjoy this lecture

There is no cis and trans order in chemistry

pKa is wicked high, but it can lower for Alkynes (I think the other word is Alkeens maybe?)

Draws examples on board

Arrow pushing that generates certain products and which side of equilibrium shold be favoured

Bronstead acid base reductions

Which side of equilibrium has the stronger acid? Water. So equilibrium is on the left hand side    battling pka

Same thing but the reverse in the bottom    keep the pka in mind. Some are stronger than others

Because of that NaNH2 – base for alkynes

You don’t want to use the old chalk from a student

More squeaky chairs, pages turn kind of violently

Several people in the class, like 7 out of the 50- 60 in here have water bottles, almost all use pencil and paper, maybe a pen

Alkyne depergonation state treat as a carbon based nucleophile,opens up a pathway to make larger molecules

Some people use a laptop

Preparation of Alkynes

Shows a reaction, there are grunts from the class. Feducai using incredibly large words. Holy shit

Be careful when counting carbons, step 2 is adding two  more carbons, product should have 6 carbons. Terminal vs internal alkynes. Wlle’ have to work

Question – well they raised their hand, but put it down

A SNEEZE

A bless you is heard

Feducia makes another joke about cis or trans to the class, they respond with  a sarcastic “trans” one kid says “both” Feducia chuckles

Drawing out more structures. This class has a nice flow to it, I can’t really say what but it works

They all seem to respect feducia, there is no noise made, they ask occasional questions, and feducia is good at teaching, like I understand a bit of this stuff

Carbon end of the CBr bond , now need to think about a bond that goes directly between them two, We’re okay with that yes?

There is a wave of nods most heavily concentrated in the front 3 rows

Oh yeah, so this classroom can probably seat 240, but I’d say there are only 70 people in here max. There is the most heavily concentrated group in the front three rows, wit nearly all those seats taken. Then the side rows are filled about row 1, then 4-7. The center of the class is nearly empty after row 4 and people sit near the aisle

Question about structures drawn on the board

I want you to take acetylene, then do the next step it’s going to be astep wise process

Another questions about Alkynes vs alkeens

Feducia walks by the one kid in the very back of the class “Hey, there are plenty of seats in the front”

Feducia does a lap around the class, makes jokes to the people as he walks. Class laughs, but I didn’t hear the jokes made

Another question about

Kid in front row talking to him, very animated Feducia chuckles, drinks a coffeesays something about things being really really tiny and breaking a hand. Then felt tip markers. Casual banter. Good relationship between him and the students

ANOTHER SNEEZE

Another blessed face

Feducia goes and

Why are we so quiet today? Say something”

Something! Cis!

More chuckles

Class seemed to liven up

Still going and explaining the board

I don’t understand these structures at all

“we add thie turbinal group to the alkyne, Yes?”

Students say Yes, but one says No

No? Why no? Then explains why the answer isno after waiting for a nonexistent response

It’s E2, that’s why.

Question Why wouldn’t the NH2 ion just do the eliminations? Wait… Whats’ the point of doing that

Why would you want to make an alkyne ion

Feducia – oh I wouldn’t! if I wanted this I’d just add these two together

Oh god say something!

We should play music

Do you want me to sing?

YES!  You can’t go back on that

Me singing sounds terrible, or like someone is beating a cat

Alkyne, Alkene. I figured it out

Going from one pi bond to two pi bonds

What am I doing here?

Elimination. Thank you

If I am adding a pi bond, what do I need to be doing in this step?
Elimination

We are going to dismantle the alkene. We have two sets of pi electrons”

Preparation of Alkynes

• From alkenes ( add^t of X_2, E2)

Looking at excess of that base if we want to force the elimination. What’s my intermediate when I run through this process?

Alkyne?

And the mechanism of that reaction looks like what?

There’s a mumble

HMM?? It’s not a free radical. Usually with the Cl2 we don’’t do reee radical, we’ll run it in the dark or in cold temp

It didn’t do that because the side with the additional addition is blocked by a chloronium ion therefor the chloride we kicked off in the first step comes back, we call that anti addition

With the linear alkenes we didn’t bother because we had 3 bonds there,

We ignore sodium, so in order to do the E2 reaction, we need the leading group and we need a leading hydrogen. So I pair up leaving groupwith a beta hydrogen. Imagin,it’s a step wise elimination process

So in that case after the first two elimination, we will be thinking about this kind of product and then the second elimination taking me to our product

So if it was in excess, we should assume that we’re generating what?

We should assume as many pi bonds as leaving

What if it wasn’t excess

Stoichiometrically, we’d have problems. We’d get here, but we’d leave some unreacted bonds

Draw the product of the following reaction

Back to observing the class. They don’t appear to be wearing anyting similar. Just like any classroom I suppose. There are some outliers

 

How many of you have that? Raise them high. Okay that’s not the product. I want you to think about why that’s not the product. Use your neighbor.

There is a chatter that can be heard in the class now

Hey, I know a kid in the second row. Nice

Anyway, the are talking to each other until they figure out the answer. Appears to have quieted down

So why won’t I create this thing in the presence of a strong base

They’ll depergonate

Right, if you have a ch bond it’s pretty acitic

I’m not the Na whisperer “only do th E2,wooo”

You can’t tell it what you want it to do, because if you set up the molecules to donly do two reactions, it could do more

So it’ll make this depergonated alkyne

So we need to use a weaker base?

But that’s fine because I am smarter than you (referring to reaction) Because I’ll just dump you in water

The product of that reaction looks very similar to what we did earlier today. Now I’m looking at the reverse reaction

NaNH2 is a pain apparently.

Okay, more other observations. There are 3 projectors, but only 2 are being used

Okay, as usual, we are over time, so if you want to go, do that now

I’ve got quiz stuff (starts handing out quizzes)

People slowly get up and pack up their bags. Not in unison at all

A min later there are still several sitting.

There is chatter all around

“like oh yeah, you sere supposed to remind me of my laptop”

Most everyone goes and collects their quiz. Rather inefficient. One man and 70 ish quizzes. Rather slow.

But they wait patiently. Others pack up, wrap cords, and move out. The door is constantly being opened and closed. Others for the next class period walk in. I wonder what class it’s for.

“I know I did the right thing. Did you ge thte one on the next page? It doesn’t make sense”

Some wait for quizzes, others wait for questions. Okay, more and more people for the next class arrive and the class has nearly dispersed. I’m heading out.

Goodbye!