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(MCPBA)

CH2Cl2

MetaChloroPeroxyBenzoic Acid

50%

50%

Racemic Mixture of Enantiomers

“Reactive Peroxy Bond”

Syn Addition

Rainbow Guard Curved Arrow Mechanism

Roche Hinge

“Oh, the things you’ll do, for the love of making bonds.”

Is that “Roche Hinge”, made of Braavosi Gold!

Rainbow Guard? Never heard of them, I’ll ask my sister.

(Click “Slideshow” to Animate)

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Major Product

Minor Product

Epoxide

Side Attacked

Less Sub. Attack

More Sub. Attack

Strong Nuc.

“Double Sided Electrophile”

“Inverts”

More Sub. Side, 3o

Less Sub.

Side, 2o

3o

Too much Steric Hindrance

No Rxn

H2O

Weak Elec.

(Ring Strain)

Major Product

Basic Conditions:

Just Attack!!

Dra-a-a-a-tik-tik!!

High Valyrian: Dracarys!!

English: Fire Attack!!

“Basic: Think - Charge Org. Intermediates”

Inverted

Less Sub.

Side, 2o

Neg. Ch. O. Intermed.

Inverted

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“Basic: Think - Charge Org. Intermediates”

Major Product

Minor Product

Epoxide

Side Attacked

Less Sub. Attack

More Sub. Attack

Very Strong Nuc. / Base

“Double Sided Electrophile”

“Inverts”

More Sub. Side, 2o

Less Sub.

Side, 1o

Major Product

Basic Conditions:

Attack!!

1a.

b. H3O+(aq)

Weak Elec.

(Ring Strain)

Very Strong Nuc. / Base

Weak Elec.

(Ring Strain)

Minor Product

Ugh, Umph!

Not Stereocenters!

Hrrrrrr!

You call an Organolithium Strong!!

Oograa!!!

Basically Steric Hind. Dominates, I agree.

Inverted

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“Acidic: Think + Charge Org. Intermediates”

Major Product

Minor Product

Epoxide

Side Attacked

Weak Elec.

Weak Nuc.

(TsOH)

More Sub. Attack

Less Sub. Attack

Strong Elec.

No Rxn

Weak Nuc.

Strong Elec.

Strong Elec.

Weak Nuc.

“Double Sided Electrophile”

“Inverts”

Major Product

Minor Product

Less Sub.

Side

Will React

Acidic Conditions:

One can’t always start with “Attack!!” as an opening, wit can also help you achieve your goals.

Yes! We need at least one Strong.

Tosic Acid, too powerful to retain its proton.

You’re showing promise in this, Game of Carbons.

More Sub. Side

Inverted

Inverted

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Acidic Conditions

Basic Conditions

“Think - Charge

Org. Intermediates”

“Double Sided Electrophile”

(Except 3o, too much S.H.)

“Side Attacked Inverts”

“Think + Charge

Org. Intermediates”

“Double Sided Electrophile”

(1o, 2o & 3o)

Need at least one Strong Nuc. or Elec.

Start with, Attack!!

Start with, Protonation to make one strong.

Strong, Hahaha..

That is one thing, I am positive of.

The Grignard Adds under Basic Conditions, the Acid is added after the deed is done.

The LiAlH4 is very Basic, the Acid is added after the deed is done.

Negative? OK, I’ll subtract you!

You “Superior” High Lords, best keep your heads in your books. It don’t look as if a sword would fit well in your, pampered hand.

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Actual Quiz on the following Slides

(Key above)

And here is a link to a Google Doc version of the Quiz.

Epoxide Synthesis and Addition Quiz (10 pts)

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Use colors for reacting electrons.

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Acidic Conditions

Basic Conditions

“Think - Charge

Org. Intermediates”

“Double Sided Electrophile”

(Except 3o, too much S.H.)

“Side Attacked Inverts”

“Think + Charge

Org. Intermediates”

“Double Sided Electrophile”

(1o, 2o & 3o)

Need at least one Strong Nuc. or Elec.

Start with, Attack!!

Start with, Protonation to make one strong.