Organic Chem II Ch 13

Order of radical stability

allylic/benzylic > 3 > 2 > 1 > methyl > vinylic

Order of carbocation stability

substituted allylic > 3 > allyl/benzyl > 2 > 1 > methyl > vinyl

conjugated diene

p-orbital next to a double bond

isolated diene

double bonds too far apart to share electrons

cummulated

double bond right next to another. p-orbitals do not align so cannot share electrons

Which is more stable, conjugated or isolated?

conjugated diene

The more substituted the…?

more stable and lower energy

What is the λ max?

tallest peak in UV-Vis

If λ max is below 200 nm

it is not conjugated

If λ max is above 200 nm

it is conjugated

1,2 and 1,4 addition are dependent on what?

temperature

1,4 addition gives rise to?

thermodynamic product (most stable but more activation energy)

1,2 addition gives rise to?

kinetic product (less stable but less activation energy so forms faster)

What does the diels-alder reaction do?

forms a 6-member ring through a 4,2 cyclo addition in a concerted fashion

What do EDG’s do to MO

Raise the energy

What do EWGs do to MOs

lower the energy

For diels-alder the diene must be?

conjugated and in s-cis conformation

Why is the endo product favored?

secondary molecular orbital overlap

What is the exo product

everything points up

What is the endo product?

substituents point down/ tuck under