Jt 1 A Uhcl Orgo Ii Exam2.1 14 Conj & Uv

Front 1

Conjugated double bonds are separated by.... bonds.

Back 1

one single bond

Front 2

Isolated double bonds are separated by... bonds.

Back 2

two+ single bonds.

Front 3

Extended conjugation leads to absorption of this type of wavelength...

Back 3

visible light

Front 4

p orbitals have two lobes, + and - indicating the opposite *** of the *** ***, not electrical charges.

Back 4

phases
wave function,

Front 5

--- Conjugated Dienes ---
Carbocations are always found as... secondary *** carbocation.

Back 5

allylic
(C adj to C=C)

Front 6

--- Conjugated Dienes ---
Of the possible cations... the nucleophile(Br-) usually attacks the.....

Back 6

most substituted cation

Front 7

*** Control
at equilibrium
controlled by the differences
in free energies

Back 7

Thermodynamic

Front 8

*** Control
irreversible - far from equilibrium
faster is formed
relative free energies of the transition states

Back 8

Kinetic

Front 9

Addition to conjugated diene @ room temp forms mostly *** adduct....
high temp form *** adduct.

Back 9

1,2
1,4

Front 10

*** is The product of an addition reaction between two compounds

Back 10

adduct

Front 11

Stability of a....
1) 1° allylic is ≈ to... this carbocation.
2) 2° allylic is ≈ to... this carbocation.

Back 11

2° carbocation
3° carbocation

Front 12

Transition state Ea for the 1,2-addition carbocation is higher/lower because it's less/more stable than 1,4.

Back 12

lower
more

Front 13

The ***-addition has the most stable product because it has the less/more substituted double bond.

Back 13

1,2
more

Front 14

--- N-Bromosuccinimide ---
1) Provides a low, constant concentration of...
2) Reacts with the *** by-product to its addition across the double bond.

Back 14

1) Br2
2) HBr

Front 15

NBR?

Back 15

N-Bromosuccinimide

Front 16

1) Allylic halides & tosylates are highly reactive substrates for SN2 reactions because...
2) Grignards and organo***s are often used...
3) H2C═CHCH2Br + CH3Li  H2C═CHCH2CH3 + LiBr

Back 16

transition state is stabilized through π conjugation
lithium

Front 17

--- Diels–Alder Reaction ---
1) Reaction between a *** w/an electrondeficient ***.
2) Producing a *** ring.
3) AKA a *** cycloaddition due to the π orbitals involved.

Back 17

1) diene --- alkene(dienophile)
2) cyclohexene
3) [4+2] cycloaddition

Front 18

--- Diels–Alder Reaction ---
1) Alkene AKA ***... can be an alkyne.
2) Its C=C MUST be conjugated w/an *** *** group.
3) Reactants align producing ***(anti/syn cis/trans) product.

Back 18

1) dienophile
2) electron withdrawing
3) endo(syn cis)

Front 19

--- Diels–Alder Reaction ---
Cyclo-penta-diene is...
1) *** if it's anti(trans) to the larger bridge and
2) *** if it's syn (cis).

Back 19

1) exo
2) endo

Front 20

--- Diels–Alder Reaction ---
1) Dienes react in the *-*** conformation
2) in a ***-step mechanism.

Back 20

1) s-cis
2) 1

Front 21

--- Diels–Alder Reaction ---
Lecture notes say #,#-product isn't possible....
only these types are...

Back 21

1,3-product
1,2 & 1-3-product

Front 22

1) A *** reaction has a transition state w/cyclic geometry and progresses in a concerted fashion.
2) An example of this reaction in this chapter is...

Back 22

Pericyclic
Diels–Alder Reaction

Front 23

--- Diels–Alder Reaction ---
1) Woodward & Hoffmann predicted reaction w/their theory of *** of *** symmetry.
2) MOs must *** constructively to stabilize the *** ***.

Back 23

1) conservation --- orbital
2) overlap --- transition state

Front 24

--- Diels–Alder Reaction ---
Diene orbitals donate/accept using the...
Dienophile orbitals donate/accept using the...

Back 24

donate --- HOMO
accept --- LUMO
Molecular Orbital

Front 25

[2 + 2] Cycloaddition is *** allowed, but *** forbidden.

Back 25

Photochemically
thermally

Front 26

--- Diene Polymers ---
1) Reaction initiators can be...
2) Latex is a # C repeat w/***
stereochemistry. Opposite to Gutta-Percha.
3)
4)

Back 26

1) radical or acid
2) 5 --- Z
3)
4)

Front 27

--- Diene Polymers ---
Charles Goodyear discovered heating w/small amount of *** produces strong material in a process called ***.

Back 27

sulfur --- Vulcanization

Front 28

--- Ultraviolet Spectroscopy ---
1) 200–400 nm photons excite e- from a π *** orbital to a *** orbital.
2) This could also be stated as from the *** to the ***.

Back 28

1) bonding --- π* antibonding
2) HOMO --- LUMO

Front 29

--- Ultraviolet Spectroscopy ---
A compound w/a longer chain of conjugated double bonds absorbs light at a *** wavelength.

Back 29

longer

Front 30

--- Ultraviolet Spectroscopy ---
β-Carotene, ### double bonds in conjugation, λmax = ### nm

Back 30

11
455

Front 31

--- Ultraviolet Spectroscopy ---
Visible region is about ### to ### nm.

Back 31

400 - 800

Front 32

--- Ultraviolet Spectroscopy ---
1) λmax increases as conjugation *** (lower energy)
2) Substituents on π system *** λmax.

Back 32

increases
increases

Front 33

--- Ultraviolet Spectroscopy ---
Energy difference between HOMO and LUMO *** as conjugation increases.

Back 33

decreases