CHEM 2443 Final

Question 1

Alkyne acid-catalyzed hydration

Answer 1

Generates a ketone
Reagents: H2SO4, H2O, & HgSO4

Question 2

Aromatic compounds

Answer 2

Conjugated planar rings w/ delocalized pi electrons
Odd number of pairs of electrons

Question 3

Nonaromatic

Answer 3

Compounds that are non-planar

Question 4

Antiaromatic

Answer 4

Compounds that have an even number of pairs of pi electrons

Question 5

Hydrogenation

Answer 5

Syn addition of H to either side of double bond
Reagents: Pd (or Pt or Ru) & H2

Question 6

Markovnikov’s rule

Answer 6

Halide prefers to bond to more substituted carbon and H prefers to bond to the carbon with the most Hs

Question 7

Alkyne hydrogenation

Answer 7

To form a cis alkene use H2, Pd/CaCO3
To form a trans alkene use Na (or Li) & NH3 (liquid)
To form an alkane use H2 & Pt

Question 8

Hydrohalogenation

Answer 8

Results in a haloalkane
Reagents: HX (use HI)
Markovnikov addition

Question 9

Dienes

Answer 9

Molecule w/ 2 carbon-carbon double bonds
Isolated: separated by 2 single bonds
Conjugated: separated by 1 single bond
Cumulated: no separation

Question 10

Halohydrin formation

Answer 10

Results in alkane with OH and X substituents
Reagents: X2 & H2O
Markovnikov for OH
anti-Markovnikov for X

Question 11

Halogenation

Answer 11

Results in alkane with two X substituents
F2 reacts fastest
Anti-addition
Reagents: X2

Question 12

Addition to dienes

Answer 12

Isolated dienes: two independent addition reactions
Conjugated dienes:
Adding HX leads to alkene with 1 X substituent
Adding X2 leads to alkene with 2 X substituents
Internal alkene is a more stable product

Question 13

Factors affecting nucleophilicity

Answer 13

More negative charge, more nucleophilicity
Less electronegativity, more nucleophilicity
Less steric hindrance, more nucleophilicity
If in an aprotic solvent, more electronegativity, more nucleophilicity for halides

Question 14

Electrophilic substitution of benzene

Answer 14

Electrophile subs for an H

Question 15

Halogenation of benzene

Answer 15

X is added
Reagents: X2 & FeCl3

Question 16

Nitration of benzene

Answer 16

NO2 is added
Reagents: HNO3 & H2SO4

Question 17

Alkylation of benzene

Answer 17

Alkyl group is added
Reagents: RCl & AlCl3

Question 18

Cahn-Ingold-Prelog priority rules

Answer 18

Higher atomic number = greater priority
If atomic numbers are equal, compare next bonded atoms

Question 19

Reacting HX w/ an Alkyne

Answer 19

If HX is in excess, results in an alkane with two X on one carbon
If one equivalent of HX, results in a haloalkene
Markovnikov addition

Question 20

Ethers

Answer 20

Molecules that have an oxygen between two alkyl groups
Oxacycloalkane: oxa + cyclo + #ane

Question 21

Alkyne hydroboration-oxidation

Answer 21

Forms an aldehyde or ketone
Reagents: 1) BH3 & THF 2) H2O2 & NaOH
Anti-Markovnikov

Question 22

Acid catalyzed hydration

Answer 22

Forms an alcohol
Markovnikov addition
Reagents: H2SO4 & H2O

Question 23

Naming priority

Answer 23

Double bond > OH > halogen > alkyl group

Question 24

Cycloalkenes

Answer 24

Cyclohexene is a half chair conformation
Rings up to 8 carbons have a cis conformation

Question 25

Sn2

Answer 25

Concerted mechanism Primary = fastest Strong nucleophile Reagents: ethoxide

Question 26

Hydroboration oxidation

Answer 26

Results in an anti-Markovnikov alcohol Reagents: 1) BH3 & THF 2) H2O2 & NaOH

Question 27

Ozonolysis

Answer 27

Cleaves double bond in half Terminal alkene: formaldehyde Mono substituted alkene: aldehyde Disubstituted alkene: ketone Reagents: 1) O3 2) H2O2 & Zn If Zn is not used, Hs attached to double bond will become OH

Question 28

Stereospecificity

Answer 28

Reaction produces a specific stereoisomer as a product

Question 29

E1

Answer 29

Tertiary = fastest Weak base Reagents (possibly): H2O & Heat (delta)

Question 30

Sn1

Answer 30

Tertiary = fastest Weak nucleophile Reagents (possibly): H2O

Question 31

E2

Answer 31

Primary = fastest Strong base Reagents: tBuO-

Question 32

Benzene

Answer 32

Molecular formula C6H6 Delocalized electrons Lots of resonance stability

Question 33

Adding an alkyl group to a terminal Alkyne

Answer 33

Reagents: 1) 3NaNH2 & NH3 (liquid) 2) RX (alkyl halide)

Question 34

Alkyne ozonolysis

Answer 34

Internal Alkyne: two carboxylic acids Terminal Alkyne: one carboxylic acid and CO2 Reagents: 1) O3 2) H2O

Question 35

Diels-Alder reaction

Answer 35

Addition of an alkene (or Alkyne) to a conjugated diene to form a cycloalkene Cyclic flow of electrons Diene has to be in cis conformation to react Stereospecific Cyclic dienes react faster

Question 36

Forming and Alkyne from a geminal or vicinal dihalide

Answer 36

Just need two equivalents of NaNH2

Question 37

Cis/trans E/Z

Answer 37

Add to front of IUPAC name Cis(Z): same side of double bond Trans(E): opposite side (usually more stable)

Question 38

Forming dienes

Answer 38

Dehydrogenation of an alkane: Cr2O3 on Al2O3 & heat (delta) Elimination reactions: need leaving groups. Acid or base and heat (delta)

Question 39

Factors affecting acidity

Answer 39

Stability of conjugate base Inductive effects Sp > sp2 > sp3 Carbon compounds are less acidic than water

Question 40

Epoxidation

Answer 40

Forms an epoxide (a three membered ring w oxygen in it) Syn addition Reagents: MCPBA

Question 41

Common benzene derived compounds

Answer 41

Phenol, Toluene, Benzoic Acid, Benzaldehyde, Anisole, Aniline