Mechanisms And Facts

Question 1

What does attack of the alkenes refer to?

Answer 1

Like EAS, alkenes attack E+ but need less motivation so no super E+ is needed, and addition occurs where a pi bond becomes 2 new sigma bonds. Reverse of elimination!

Question 2

How to add a sigma bonded halogen?

Answer 2

Halo-hydrin (HBr), (syn/anti) Mar (C+)

Question 3

What is Markovnikov’s rule

Answer 3

Put + or carbocation on most stable position, first sigma (H) on less substituted carbon

Question 4

How to add an alcohol sigma bond

Answer 4

Hydration (H2O, cat. acid), Syn/anti Mar (C+)

Question 5

What is Markovs addition?

Answer 5

Add -OH on most substituted

Question 6

Syn addition

Answer 6

Nu only attacks same side as first group (maybe bc mechanism)

Question 7

Anti addition

Answer 7

Nu only attacks opposite side from 1st group, (something in way on other side?)

Question 8

How to add an alcohol with r group

Answer 8

Basically hydration (R-OH, cat. acid), Syn/anti, Mar (C+)

Question 9

How to add two halogens

Answer 9

Halogenation (X2), Markov addition, Anti; polarizability is why no catalyst is needed

Question 10

How to add a halogen and alcohol

Answer 10

Halo-hydration (X2, H2O), Anti, Mar; similar halogenation but done in weak Nu solvent, X is better Nu but there is so much water that H2O is added

Question 11

How to add OH without rearrangement

Answer 11

Mercuration* (1)Hg(OAc)2, H2O 2)NaBH4), Anti, Markov addition with no rearrangement

Question 12

How to add OH group to less substituted position (not base)

Answer 12

*(1)BH3 2) HOOH/OH-), syn, non markov add bc mechanism and sterics

Question 13

How to make an alkene into an alkane

Answer 13

Hydrogenation* (H2 gas, Cat. Pd/C), syn

Question 14

Answer 14

Question 15

How to control the second addition at will

Answer 15

Epoxides (mCPBA)

Question 16

How to make epoxide which inverts steriochem 2 x

Answer 16

(1)Br2 in H2O 2) LDA), anti

Question 17

Difference in additions

Answer 17

Question 18

How to attack less hindered in epoxide

Answer 18

Base no carbocation so attacks less hindered spot

Question 19

How to attack most stable in epoxide

Answer 19

Acid bc carbocation is formed

Question 20

How to break c-c bond

Answer 20

Cleaver*, ozonolysis

Question 21

How to make ozone

Answer 21

Ozonolysis, ozone breaks down molecules bc its super reactive, DMSO is stable, Malozonide (3 O right next to each other) intermediate is super unstable

Question 22

Difference in external and internal alkynes

Answer 22

External has a relatively acidic proton which is removed by strong bases. Both have 2 pi bonds to react

Question 23

How to make alkynes

Answer 23

Internal Br2 2 eq LDA
External Br2 3 eq LDA and H2O

Question 24

How to make geminal dibromide

Answer 24

Question 25

How to add 4 Br

Answer 25

Halogenation with alkenes (Br2)

Question 26

How to make a ketone

Answer 26

Alkyne hydration (H2O, Cat. H2SO4), enol tautomerizes keto aldehyde, water best nu and base

Question 27

Mercuration with alkyne

Answer 27

Cant do that

Question 28

Non markov add for aldehyde

Answer 28

(1)BH3 2) NaOH, HOOH) Makes aldehyde

Question 29

How to add H2 to alkyne

Answer 29

Hydrogenation, H2 with pd/c, lindlars, then Na and NH3

Question 30

How to break an alkyne

Answer 30

Cleaver (1) O3 2) SMe2, 3 bonds O each

Question 31

Practice oxidation here, what is it?

Answer 31

Look for H on home C, add more bonds to O (from H)

Question 32

Strong oxidizing agent on secondary

Answer 32

Jones (H2CrO4, H2O)

Question 33

Strong oxidizing agent with primary

Answer 33

Jones, needs OH group as enabler, water is best Nu

Question 34

Oxidize primary alcohol once

Answer 34

No water bc if there is any it makes a geminal diol (no second oxidation without water), PCC can only make ketones or aldehydes

Question 35

Reminders

Answer 35

Question 36

Add OH with multiple groups present

Answer 36

Tollens reagent, (Ag2(OH), NH4OH), reacts with double bonded O’s C

Question 37

Carbon connected to benzene reactivity

Answer 37

Benzylic resonance stabilized leads to more reactivity

Question 38

Add carboxylic acid to ring

Answer 38

Jones, good to bad group, changing activation group

Question 39

Complete the rxns

Answer 39

Question 40

Solve

Answer 40

Question 41

Add halogen next to carbonyl

Answer 41

Tetrahedral intermediate (SOCl2, cat. Py)

Question 42

Solve

Answer 42

No… OH, never use OH with LDA bc takes proton

Question 43

Solve

Answer 43

Question 44

How to form an ester, what happens if base present

Answer 44

Question 45

3 ways make this

Answer 45

Question 46

How many solutions

Answer 46

Usually 4 but 2 same, syn or ant make 2