Exam 3 other info

Question 1

E in german

Answer 1

entgegen, opposite

Question 2

Z in german

Answer 2

zusammen, same

Question 3

heat of hydrogenation

Answer 3

heat released during hydrogenation

allows us to ID stability

higher the heat of hydrogenation, the lower the alkene’s stability

Question 4

why are more substituted alkenes more stable?

Answer 4

inductive effects and hyperconjugation

Question 5

cycloalkenes with 5 C or fewer only…

Answer 5

exist in cis form

Question 6

trans cyclo____ can be isolated and exists as enantiomers

Answer 6

octene

Question 7

for trans cyclo—- and higher C number, cis is just as stable as trans

Answer 7

decene

Question 8

Bredt’s rule

Answer 8

bicyclic compounds cannot have double bond at bridgehead unless one ring has 8 C or more

(if they do, they’re unstable)

Question 9

Zaitsev’s rule

Answer 9

if more than one elimination product (alkene) is possible, the most substituted alkene is the major product

Question 10

if you have to start an E2 rxn with a 1° halide…

Answer 10

use a bulky base

Question 11

config. required for E2 to occur

Answer 11

anticoplanar

Question 12

catalytic cracking

Answer 12

long chain alkane broken into a smaller alkane and an alkene

alkene is purified

Question 13

dehydrogenation

Answer 13

removal of H2 from alkane to give alkene

requires a lot of energy

Question 14

regioselectivity yields…

Answer 14

2+ constitutional isomers, with one being the major product

Question 15

THF

Answer 15

tetrahydrofuran

Question 16

2 types of halogenation

Answer 16

in anhydrous conditions - yields doubly halogenated product

in aqueous conditions - yields halohydrin (OH and X)

Question 17

hydrogenation requires…

Answer 17

heat, pressure

Question 18

catalysts used in hydrogenation

Answer 18

Pt, Pd, Ni

Question 19

heterogeneous catalysis

Answer 19

substrates in different phases

insoluble catalyst

fine particles of catalyst react with substrate to form products

Question 20

homogenous catalysis

Answer 20

catalyst is soluble

Question 21

4 types of information you can get from NMR

Answer 21

1. # of signals – types of nuclei
2. chemical shift – chemical environment
3. area under signal – number of nuclei contributing
4. splitting pattern – number of neighbors

Question 22

unit used to designate chemical shift

Answer 22

𝛅

Question 23

TMS

Answer 23

tetramethylsilane

reference compound

Question 24

moves signal downfield

Answer 24

deshielding

Question 25

multiplicity =

Answer 25

n + 1

Question 26

used to determine split peak height

Answer 26

Pascal triangle

Question 27

only — % of C is 13C

Answer 27

1.1%