Final exam Flashcards
1
Q
What does HONC tell you?
A
How many bonds those atoms want to be neutral
- 1,2,3,4
2
Q
chpt 12
Why do alcohols have a high bp?
A
because of the hydrogen bonding
3
Q
chpt 12
Alkoxides
A
conjugate bases of alcohols, RO- groups
4
Q
chpt 12
What kind of bases are needed to deprotonate an alcohol?
A
C-, N-, H-
all very strong bases
5
Q
chpt 12
CARIO
A
charge
atom
resonance
induction
orbital
6
Q
chpt 12
when can you use substitution to form an alcohol?
A
only with a 1 or 3 substrated
2 would prompt elimination
7
Q
chpt 12/chpt 8
what are the three ways an alcohol can be prepared via addition?
A
- acid cataylyzed (Dilute H2SO4)
- Hydroboration oxidation (BH3 THF)
- Oxymercuration demurcuration (Hg(AcO))
8
Q
chpt 8
what is the intermediate for acid cataylyzed hydration of an alkene?
A
carbocation
be aware of rearrangements
9
Q
chpt 8
Which one is markovnikov addition? Hydroboration or Oxymerucuration?
A
Oxymercuration
Hg(AcO)
10
Q
chpt 12
Oxidation
A
increase in the number of C-e- atom bonds
decrease in the number of C-H bonds
11
Q
chpt 12
reduction
A
increase in the number of C-H bonds
decrease in the number of C-e- atom bonds
12
Q
chpt 12
What are the four reducing agents we know to change a ketone or aldehyde to a alcohol?
A
- LAH (strongest)
- NaBH4 (mild)
- H2 + metal catalyst
- grignard reagent
13
Q
chpt 12
can LAH reduce carboxlyic acids and esters?
A
yes, it is strong enough. BH4 is not.
14
Q
chpt 12
When do you need a protecting group with a grignard reagent?
A
When the group you are trying to react with contains an acidic proton
15
Q
chpt 12
What are the reagents for adding a protecting group for a grignard reagent?
A
TMSCl +NE3+
16
Q
chpt 12
What are the reagents for removing a protecting group for a grignard reagent?
A
TBAF
17
Q
chpt 12
SOCl2 +PBr3 and a 1 or 2 alcohol =
A
a 1 or 2 alkyl halide
they just add the halogen to where the alcohol was
18
Q
chpt 12
What are the two key oxidzing reagents we know?
A
PCC and Chromic acid
chromic acid stornger than PCC
19
Q
chpt 13
Why are ethers often used as organic solvents?
A
bc they are not very reactive and have low bps
20
Q
chpt 13
Williamson ether synthesis
A
makes an ether from an alcohol group
1. pt to create alkoxide
2. nuc attack on alkyl halide
21
Q
chpt 13
Alkoxymercuration demurcuration
A
similar to oxymerucration but ads a RO group instead of an OH group
22
Q
chpt 13
Acidic cleavage of ethers
A
- heat + strong acid
- converts an ether to two alkyl halides
23
Q
chpt 13
What happens when a phenyl ether undergoes acidic cleavage?
A
one alkyl halide + one phenol
24
Q
chpt 13
halohydrin +NaOH =
Br and OH must be anti to each other
A
creates an epoxide through an intermolecular reaction
25
# chpt 13
what are the two ways to open epoxides?
1. epoxide attacked by good nuc
2. acid catalyzed ring opening
26
# chpt 13
mechanism for opening of an epoxide using a good nucleophile
| base catalyzed
1. nuc attack
2. proton transfer
27
# chpt 13
mechanism for acid catalyzed opening of an epoxide?
1. proton transfer
2. nuc attack
28
# chpt 13
if you have a primary and tertiary side of an epoxide which side will be attacked during acid catalyzed ring opeing?
the 3 side because of electronic effects
29
# chpt 13
is sterochem conserved during acid catalyzed ring opening of an epoxide?
yes, conserved but inverted
30
# chpt 13
how do you prepare a thiol?
alkyl halide + NaSH = thiol
31
# chpt 13
How do you prepare a disulfide?
1. Pt to make thiolate
2. nuc attack by thiolate on halogen (Cl2, Brs)
3. nuc attack by another thiolate
4. pt for neutralization
32
# chpt 13
disulfide
two sulfur atoms adjacent on a molecule
33
# chpt 3
the --- the pka value the weaker the acid
higher
34
# chpt 3
equilibrium will move --- from the strong acid/base
away
35
# chtp 3
strong acid create --- bases
weak
36
# chpt 3
weak acids come from --- bases
strong
37
# chpt 3
Is a terminal alkyne or an amine more stable?
alkyne is more stable because of s character
| CARIO exception
38
# chpt 3
True or false? In a reaction with H2O and Cl- the reaction will favor the side the water
false, con bases of HCl are more stable than neutral water
| cario exception
39
# chpt 3
Lewis acid
electron pair acceptor
40
# chpt 3
Lewis base
electron pair donor
41
# chpt 4
What is a Newman projection
used to draw the conformation of a molecule from a specific pov, a front carbon and a back carbon
42
# chpt 4
Staggard conformation
when the groups in a newman projection are equally spaced with no strain
43
# chpt 4
eclipsed conformation
in a newman projection where the groups are close together, lots of strain
44
# chpt 4
Torsional strain
torsional = twisted
strain that is only found in eclipsed conformations
45
# chpt 4
Steric Strain
strain that can happen in eclipsed or staggard conformation, two groups that are not H are interacting
| ex: an ethyl and a methyl interacting
46
# chpt 4
Gauche conformation
staggard conformation that has steric strain
47
# chpt 4
Why is the chair conformation the most stable/ strongest hexane conformation?
no ring strain, no torsional strain, no angle strain
48
# chpt 4
True or false? every hexane can have only one chair conformation
false, every hexane can have two and only two chair conformations
49
# chpt 4
What do you look for when considering what the most stable chair conformation is?
1. are the largest substiuents equitorial?
2. what are the interactions of the substituents?
50
# chpt 4
Steroisomers
molecules that differ in their spatial arrangment of atoms
51
# chpt 16
What is the difference between conjugated and cumulated dienes?
conjugated have a sigma bond separating the two double bonds
cumulated are pi bonds right next to each other
52
# chpt 16
How do you prepare a diene?
1. double elimination with two adjacent halogens and a strong bulky base
2. single elimination with a pi bond and one adjacent halogen and a strong bulky base
52
# chpt 16
Isolated dienes
pi bonds separated by 2 or more sigma carbon bonds
52
# chpt 16
diene +HX =
pi bond + adjacent halogen
53
# chpt 16
mechanism for addition of H + X to a diene
1. pt to create resonance stabilized c+
2. nuc attack by X- on both resonance structures
54
# chpt 16
Thermodynamic product
the product favored at high temperatures, the most stable alkene
| most stable usually = most substituted
55
# chpt 16
kinetic product
product favored at low temperatures, most stable c+
56
# chpt 16
is the diels alder reaction concerted or stepwise?
it is a peri cylic reaction so it is concerted
57
# chpt 16
Is diels alder favored at high or low temperatures
at low temperatures the forward reaction is favored
| reverse at high temps
58
# cht 16
What makes a good diene for diels alder?
you need the diene to be cis for reaction so one locked into a ring will react faster
59
# chpt 16
what makes a good dieneophile for diels alder?
dienophiles with ewg lower the activation energy to react faster
60
# chpt 16
explain the endo and exo prefrence for diels alder products
endo: favored bc it is close to the pi bond of the product
exo: not favored
61
# chpt 17
If you have a molecule with a chain that is longer that 6 carbons + a benzene ring what will you use for the parent name?
if the chain is longer than 6 carbons the chain will be the parent, not the ring
62
# chpt 17
ortho
adjacent to each other, no carbons apart
63
# chpt 17
meta
substituents that are one carbon apart
64
# chpt 17
para
substituents that are two carbons apart
65
# chpt 17
Why is benzene so stable?
because of its 6 overlapping p orbitals
- all bonding MOs filled
66
# chpt 17
What does huckles rule state?
a ring must have an odd number of pi bonds to be aromatic
67
# chpt 17
How do you draw a frost circle?
1. draw a circle
2. draw the molecule you are refrencing to with the pint down
3. draw a line through each intersecting point in the shape to get all your bonding, anti bonding and non bonding MOs
68
# chpt 17
toluene
benzene with a methyl
69
# chpt 17
anisole
benzene with a methyl ether
70
# chpt 17
styrene
benzene with an ethyl that has a 1-2 pi bond
71
# chpt 17
Anti aromatic
if the molecule does not satisfy the 4n+1 rule, has an even number of pi bonds
- rings of 5 atoms or less
72
# chpt 17
non aromatic
rings with 6 atoms or more than can change their shape to avoid antiaromaticity
- not fully conjugated
- follow huckles rule
73
# chpt 17
positive charges on rings do what for orbtials?
it frees up a orbital and still participates in conjugation
74
# chpt 17
negative charges do what for orbitals?
fills an orbital that participates in conjugation
75
# chpt 17
Do localized electrons count towards huckles number of electrons?
No, bc they do not participate in resonance
76
# chpt 17
Alkyl benzene + chromic acid
| or KMnO4
benzoic acid
- benzoic position is completely oxidized to a carb acid
77
# chpt 17
Can a benzylic carbon with no protons be oxidized?
No, there must be a benzylic proton present
78
# chpt 17
alkyl benzene + NBS and heat
allylic/adjacent bromination, bromine added to benzylic position
79
# chpt 17
Benzene ring + 3Eq H and lots of pressure
comletely reduced, all pi bonds removed
| poof
80
# chpt 18
EAS/ electrophilic aromatic substitution
one of the protons on the benzene is replaced with an electrophile
81
# chpt 18
Does bezene act as a nucleophile or electrophile in EAS?
nucleophile
82
# chpt 18
Mechanism for halogenation by EAS
1 nuc attack by benzene
(resonance structures)
2. pt to restore aromaticitiy
83
# chpt 17
What does it mean when you say aromatic moiety is preserved?
the molecule starts aromatic and ends aromatic
84
# chpt 5
constitutional isomers
same formula different connectivity
85
# chpt 5
sterosiomers
same formula and connectivity but different spacial arrangements of atoms
86
# chpt 5
chiral
to be non superimposable on your mirror image (can rotate polarized light)
| eg: hands
87
# chpt 5
achiral
superimposable over your mirror image
88
# chpt 5
all chiral centers are stereocenters but -----
not all stereocenters are chiral centers
89
# chpt 5
what hybridization of an atom often yields a stereocenter?
an sp2 atom attatched to a double bond is often a stereocenter
| either both atoms of the double bond are or neither of them
90
# chpt 5
enantiomers rotate light in equal but ---
opposite directions
91
# chpt 5
How do you determine the number of stereoisomers in a molecule?
2^n rule
n= number of chiral centers
- plane of symmetry: subtract one from 2^n number
- count the 2 stereoisomers on either side of pi bond as 1
92
# chpt 5
Meso compound
two or more chiral centers with a plane of symmetry
93
# chpt 6
enthalpy
the exchange of energy between a system and its surroundings
94
# chpt 6
entropy
the measure of disorder in a system
95
# chpt 6
what favors a spontaneous reaction?
exothermic, negative enthalpy
increase in disorder, positive entropy (opposite sign of G)
96
# chpt 6
What does endergonic mean?
that there is energy absorbed, reactants are lower in E than products
| non favorabole
97
# chpt 6
what does exergonic mean?
that energy was lost, reactants are higher in E than products
| favorable
98
# chpt 6
spontaneous does not mean ---
fast, it can be slow and still be spontaneous
99
# chpt 6
What kinds of things affect the rate of a reaction?
1. activation energy of reaction
2. temperature
3. sterics of molecules that are reacting
100
# chpt 6
by looking at a reaction coordinate diagram how can you tell how many transition and intermediate states there are?
transition states are the top of the hills
intermediates are 'in the well' they are the dips in the graph
101
# chpt 6
The number of transition states tell you what?
how many mechanistic steps there are
102
# chpt 6
hammonds postulate
in an exergonic reaction the reactants resemble the transition states
in an endergonic reaction the products resemble the transition states
103
# chpt 6
What makes a good nucleophile?
small, and unhinderd with lots of electron density
104
# chpt 6
What makes a good electrophile?
electron deficent, positve charge
105
# chpt 18
What is the intermediate for EAS?
sigma complex
106
# chpt 18
Reagants for Sulfonation by EAS?
SO3 +H2SO4= SO3H on a benzene ring
| extra pt step
107
# chpt 18
Nitration by EAS
benzene ring + HNO3 and H2SO4 = NO2 on a benzene ring
108
# chpt 18
Friedel Crafts Alkylation
adding a alkyl group to a benzene ring
- alkyl halide + benzene ring and lewis acid
109
# chpt 18
Why is a lewis acid so important for the friedel crafts alkylation?
the lewis acid makes the halide more electrophilic
110
# chpt 18
If the alkyl halide for friedel crafts is not 2 or 3 what happens?
there will likley be C+ rearrangments unless its a methyl group
| halide must also be sp3 to react
111
# chpt 18
Friedel crafts acylation
- adding a acyl (C=O) group to a benzene ring using an acid halide + Lewis acid + benzene ring
112
# chpt 18
True or false? Acylation will undergo polyacylation like how alkylation will undergo polyalkylation
False, acylation does not undergo poly reactions
113
# chpt 18
clemmensen reduction
A benzene ring with a C=O group attatched has the C=O group completely removed by HCl and Zn
114
# chpt 18
How do most activators direct?
ortho, para directors
115
# chpt 18
How do most deactivators direct?
para
| not halogens tho
116
# chpt 18
Strong activators
lone pair that can only resonate within the ring
| O minus, N minus groups
117
# chpt 18
Medium activators
lp that can resonate inside and outside the ring
| esters, ethers
118
# chpt 18
weak activators
alkyl groups that donate via hyper conjugation not resonance
119
# chpt 18
Strong deactivators
NO2, CX3, any N+ atom
120
# chpt 18
Moderate deactivators
acyl groups with a double bond that is part of the congjuation of the ring
121
# chpt 18
weak deactivators
halogens that deactivate via induction, not resonance
| ortho para directors
122
# chpt 18
Always follow the directing of the ---- ----
strongest activator
123
# chpt 18
Examples of blocking groups
sulftonation is a popular blocking group because it can be easily removed by dilute H2SO4
124
# chpt 18
When can nitration NOT be performed?
when there is an amine or alcohol group already present
125
# chpt 18
How do you reduce nitrobenzene to aniline?
Fe/ Zn and HCl
126
# chpt 18
NAS, nucleophilic aromatic subtitution
the ring acts electrophilic in these reactions and is attacked by a nucleophile
127
# chpt 18
What are the three qualifications to undergo NAS?
1. nitrogroup must be present
2. LLG and nitrogroup must be ortho or para to each other
3. LG must be a good LG
128
# chpt 18
Mechanism for NAS
1. nuc attack
(resonance pattern)
2. LLG
129
# chpt 18
What is the intermediate for NAS?
meisenheimer complex
130
# chpt 18
Elimination addtion
this is used for addition to a ring when there is not a NO2 group present to perform NAS
131
# chpt 18
mechanism for elimination addition
1. pt to create lp
2. LLG
3. nuc attack
4. pt to restore aromaticitiy
132
# chpt 19
Why are aldehydes better electrophiles than ketones?
because they dont have two alkyl groups to stabilize and create steric hinderence
133
# chpt 19
Hydrate formation in acidic condtions
| two OH on the same carbon
Ketone/aldehyde + H2O
- pt to create strong electrophile
- nuc attack
- pt for neutral product
134
# chpt 19
Hydrate formation under basic conditions
| two OH attatches to same carbon
ketone/ aldehyde + NaOH
- nuc attack
- pt
135
# chpt 19
Acetal formation
| two R-O groups on the same carbon
ketone/ aldehyde + excess R-OH group = acetal
- pt to create better electrophile
- nuc attack
- pt to create neutral intermediate
(hemiacetal is formed)
- pt to create good LG
- nuc attack
- LLG
- pt for neutral product
136
# chpt 19
How are acetals easily removed?
an acetal treated with water will be removed
| makes good blocking group
137
# chpt 19
Imine formation
ketone/aldehyde treated with a primary amine
138
# chpt 19
Imine mechanism
1. nuc attack by amine
2. proton transfer
3. proton transfer to create neutral intermediate
(carbinol formed)
4. proton transfer to create good LG
5. LLG
6. proton transfer to create neutral product
139
# chpt 19
Wolf Kishner reduction
imine treated with heat and a strong base reduces completley to an alkane
| poof imine gone
140
# chpt 19
enamine formation
ketone/aldehyde + secondary amine
141
# chpt 19
Mechansim for enamine formation
1. nuc attack
2. proton transfer
3. proton transfer for neutral intermediate
4. pt for better LLG
5. LLG
6. pt to create adjacent double bond
142
# chpt 19
Cyanohydrin formation
| CN +OH attatched to same carbon
HCN + ketone/aldehyde = cyanohydrin
- nuc attack
- pt
143
# chpt 19
Wittig reaction
ketone/aldehyde + witting reagent/ylide = alkene where C=O bond was
144
# chpt 19
is the witting reagent a carbon nucleophile or a phosphorus electrophile?
it is a carbon nucleophile
145
# chpt 19
Bayer Village oxidation
ketone + peroxy acid = ester formation
146
# chpt 19
for the bayer village reaction what is the order of prefrences?
H>3>2>ph>1>methyl
147
# chpt 20
True or false? carb acids are flat
True
148
# chpt 20
True or false? ewg destabilize acids, making them stronger
false, ewg stabilize acids making them weaker
149
# chpt 20
What are the four ways to make a carb acid?
| not including hydrolysis of derivatives
1. Ozonolysis of terminal alkynes
2. oxidation of a primary alcohols with chromic acid or KnMO4
3. oxidation of a benzlyic carbon with chromic acid
4. CO2 + grignard reagent
150
# chpt 20
Mechanism for reduction of a carb acid to a alcohol using LAH/ BH3 THF
1. pt to create carboxylate
2. weird AlH2 and carb acid structure to create aldehyde (elimination)
3. nuc attack by LAH
4. pt to neutralize
151
# chpt 20
List the carb acid derivatives we know in order of most reactive to least
1. acid halide
2. acid anhydride
3. ester
4. amide
5. nitrile
152
# chpt 20
nucleophilic acyl substitution
nuc attack on a carb acid to replace the OH group with something else
153
# chp 20
Where are the three places a pt will occur? for nucleophilic acyl subtituion
1. before nuc attack if in acidic conditions
2. between nuc attack and LLG for good LG
3. After LLG if your nucleophile is neutral
154
# chpt 20
How can you prepare a acid halide?
carb acid (and other molecules) + SOCl2
155
# chpt 20
Hydrolysis (acid or base) of any carb acid derivative will yield?
a carb acid
156
# chpt 20
Alcoholysis of acid halides
acid halide + OH group = ester
157
# chpt 20
Aminolysis of acid halides
acid halide + amine = amide
158
# chpt 20
Reduction of acid halides
haldie + LAH and H3O = primary alcohol
acid halide +LiAl(OR)3 = stop reduction at aldehyde
acid halide + R2CuLi= stop reduction at ketone
acid halide + grignard = tertiary alcohol
159
# chpt 20
Preparation of acid anhydrides
acid halide + carboxylate = acid anhydride
160
# chpt 20
Four ways to prepare ester
1. SN2
2. Bayer Village reaction
3. fischer esterification
4. alcoholysis of acid halides
161
# chpt 20
Mechanism for saponification of esters
1. nuc attck
2. LLG
3. pt
4. pt to restore carb acid
162
# chpt 20
Mechanism for acid hydrolysis of esters
1. pt
2. nuc attack
3. pt
4. pt
5. LLG
6. pt
| - same for esterification but with an OH group
163
# chpt 20
three ways to reduce esters
1. ester + xs LAH = primary alcohol
2. ester + grignard = tertiary alcohol
3. ester + DIBAH = stops at the aldehyde
164
# chpt 20
amide + xs LAH =
amine
| imine intermediate
165
# chpt 20
Two ways to prepare nitriles
1. amide + SOCl2
2. NaCN + alkyl halide
166
# chpt 20
Nitriles + grignard reagent
ketone
| imine intermediate
167
# chpt 20
Nitriles + xs LAH =
amine
168
# chpt 21
which hydrogens are the most acidic on carbonyl containing compounds?
alpha hydrogens which are on the alpha carbons that are adjacent to the carbonyl containg carbon
169
# chpt 21
Enols
Overall neutral molecules that tautomerize with ketones
170
# chpt 21
stabilizing factors for enols
1. an enol with conjugation
2. an enol that is aromatic
3. an enol that can form intermolecular hydrogen bonds
171
# chpt 21
enolates
over all negativley charged, often act as nucleophiles in reactions
172
# chpt 21
What are the two nucleophilic sites on a enolate and which one has the favored attack?
C and O nucleophilic sites, C- attack is favored
173
# chpt 21
What bases are used for irreversible enolate formation?
LDA and NaH
174
# chpt 21
Mechanism for acidic alpha halogenation
1. pt
2. enol formation
3. nuc attack by enol pi bond on Br2
4. pt for neutral product
175
# chpt 21
Does acid alpha bromination monobrominate or polybrominate?
it mono brominates at the more substitued position
176
# chpt 21
Does basic alpha halogenation monobrominate or polybrominate?
it will brominate until there are no longer alpha hydrogens at the least substitued postion
177
# chpt 21
What is the product of a ketone with three alpha hydrogen protons undergoing basic alpha halogenation?
a carboxylic acid
178
# chpt 21
Hell Volhard Zelinsky reaction
carb acid + PBr3 and Br2= Br at the alpha position of the carb acid
179
# chpt 21
Aldol addition reaction
aldehyde or ketone reacts with itself in basic conditions to form an aldehyde and alcohol group on one molecule
180
# chpt 21
Ways to keep crossed reactions from getting too messy
1. have a reagent with no alpha protons
2. treat with LDA or NaH to get irreversible enolate formation
181
# chpt 21
Aldol condensation
Aldol treated with a base and heat to get a pi bond and loss of the OH group in the form of water
182
# chpt 21
What is the driving force behind aldol condensation?
to create conjugated pi systems and improve stability through conjugation
183
# chpt 21
We know that aldol condesations are favored at most temperatures, at what temperatures are they not favored?
at very low temperatures (-10 C) may be low enough to not completley favor the aldol condensation
184
# chpt 21
What kind of rings are favored to form in diekmann and aldol intramolecualr reactions?
5, 6 membered rings
185
# chpt 21
Claisen condensation
Aldol condensation but with ethers which leaves a ketone and one ether
186
# chpt 21
What is necessary for the claisen condensation to happen?
1. NO NaOH
2. base must match ether R group
3. at least 2 alpha protons present
187
# chpt 7
substitution reactions
nucleophilic attack + loss of a leaving group
188
# chpt 7
elimination reactions
forms a pi bond via pt and LLG
189
# chpt 7
True or false? SN2 prefers unhinderd, non sterically hindered substrates
true, SN2 is the only one that prefers nosteric hinderence
190
# chpt 7
SN2 and E2 are both --- reactions
concerted reactions
191
# chpt 7
What makes a good nucleophile?
1. charged = more e- density
2. polarizibility aka how well they stabilize a charge
3. size, smaller nucleophiles are stronger
192
# chpt 7
Polar protic solvent
has hydrogen bonding and creates a solvent shell around nucleophile
- only favored by unimolecular reactions
| bad for bimolecular reactions
193
# chpt 7
Polar aprotic solvent
has no hydrogen bonding, does not create a solvent shell around nucleophile
- favorable by bimolecular reactions
194
# chpt 7
(for E2) the more highly substitued the base the more likely the product will be --- substituted
less
195
# chpt 7
Zaitsev product
more substitued alkene
196
# chpt 7
Hoffman product
less substitued alkene
197
# chpt 7
What sterochemistry is necessary for elimination reactions?
the leaving group and proton need to be anti, if not the E2 reaction will not proceed
198
# chpt 7
what stereochemistry is necessary for E2 to happen on a ring?
the leaving group and proton must be anti AND leaving group has to be axial if not E2 will not happen
199
# chpt 7
How do unimolecular reactions differ from bimolecular
they are stepwise (rearrangements) and only rely on one thing (concentration of substrate) vs two things
200
# chpt 7
What promotes unimolecular reactions
- polar protic base
- 3 substrate with a weak base/ nucleophile
201
# chpt 7
sterospecific
only one stereoisomer is formed
202
# chpt 7
stereoselective
both stereoisomers are made but one is favored
203
# chpt 7
Regiospecific
only one product is formed, only one place on the molecule is reacted
204
# chpt 7
regioselective
two products are formed, two possible areas on the molecule to react
205
# chpt 7
Is the zaitsev or hoffman product favored by E1?
zaitsev always favored for E1
206
# chpt 7
Is zaitsev or hoffman favored by E2
with a bulky base hoffman is favored but other wise zaitsev is favored
207
# chpt 7
when turning an O into a better LG with TsCl is there inversion of the carbon?
no, bc its reacting with the O not the carbon
208
# chpt 8
Addition reactions
adding two groups to either side of a pi bond
209
# chpt 8
alkenes can act both as weak --- and ---
bases and nucleophiles
210
# chpt 8
Addditions are favored at --- temperatures
low temps
| elimination is favored by high temperatures
211
# chpt 8
Hydrohalogenation addition
H and X added across an alkene
- markovnikov reaction
212
# chpt 8
Acid catalyzed hydration of an alkene
add of H and OH across a pi bond
- H3O+ and an alkene
| markovnikov addition
213
# chpt 8
Hydroboration Oxidation
BH3
- addition of OH and H across a pi bond
| anti markovnikov
214
# chpt 8
Does hydroboration oxidation undergo syn or anti addition?
only syn addition
215
# chpt 8
Oxymercuration Demercuration
Hg(OAc2)
- addition of water across a pi bond
| markovnikov addition
216
# chpt 8
Catalytic Hydrogenation
H2 and a metal catalyst to add H across a pi bond
217
# chpt 8
does catalytic hydrogenation have syn or anti addition?
syn addition bc of the intermediate (space ship, metal coordinates with alkene)
218
# chpt 8
Halogenation of alkenes
two halogens added across a pi bond using Cl2 or Br2
219
# chpt 8
does halogenation of an alkene do syn or anti addition
anti, bc of cylic intermediate
220
# chpt 8
why do cylic intermediates result in anti addition?
bc the ring takes up all the space on either the top or the bottom of the molecule
221
# chpt 8
Halohydrin addition
O-R + X across a pi bond
| O added to more substituted position
222
# chpt 8
Does the halohydrin reaction do syn or anti addition?
anti bc of cyclic intermediate formed
223
# chpt 8
Dihydroxylation reaction
addition of two OH groups across an alkene
- can be anti or syn addition
224
# chpt 8
anti dihydroxylation
MCPBA/ Peroxy acids
225
# chpt 8
syn dihydroxylation
Osmate ester/ cold potassium permangenate
| concerted process
226
# chpt 21
alkylation of the alpha position
alkyl halide + ketone/aldehyde = ketone/aldehyde with additional carbons
227
# chpt 21
mechanism for alkylation of the alpha position
1. pt to form enolate
2. nuc attack by enolate on alkyl halide`
228
# chpt 21
True or false? alkylation of the alpha position is an SN1 reaction
false, it is an SN2 reaction
229
# chpt 21
How do you form the kinetic product for alkylation of the alpha position
LDA and cold temps (-78 C)
230
# chpt 21
How do you form the thermodynamic product for alkylation of the alpha postion?
NaH at warm temperatures (25 C)
231
# chpt 21
Maloic ester synthesis
diethyl malonate treated with an akyl halide and then heated with acid yields a carb acid with additional carbons
232
# chpt 21
Mechanism for Malonic ester synthesis
1. formation of the enolate
2. nuc attack by enolate on alkyl halide
3. hydrolyze esters into carb acids
4. heat to yield CO2 and a carb acid with additional carbons
233
# chpt 21
Acetoacetic Ester Synthesis
ethyl acetoacetate + alkyl halide = ketone
234
# chpt 21
Mechanism for Aceotacetic ester synthesis
| similar to Malnoic ester synthesis
1. formation of enolate
2. nuc attack by enolate on alkyl halide
3. hydrolyze the one ester into carb acid
4. heat to yield CO2 + ketone
235
# chpt 18
What are the issues with friedel crafts alkylation?
1. if halide is not 2 or 3 rearrangments will occur which slow the reaction down
2. polyalkylation is possible
3. some rings are too deactivated to be added to
236
# chpt 21
Conjugated addition reactions
using the products of aldol condensation as electrophile bc of their 2 and 4 reaction positions to get alkylated ketones
237
# chpt 21
An attack at the 4 position is a --- ---
conjugated attack
238
# chpt 21
An attack at the 2 position is a --- ---
direct attack
239
# chpt 21
A strong nucleophile/ strong base used in conjugated addtion reactions gives what?
1'2 attack
| kinetic product
240
# chpt 21
A weak nucleophile/base used in conjugated addition reactions gives what?
1'4 attack
| thermodynamic product
241
# chpt 21
Mechansim for conjugate attack
1. nuc attack by michael donor at 4 position
2. pt to form enol
3. tautomerization
242
# chpt 21
Michael reactions
michael donors attack michael acceptors to form alkylated ketones
243
# chpt 21
examples of michael donors
doubly stabilized enolates, R2CuLi, C- NO2 molecule
244
# chpt 21
Stork Enamine synthesis
converting a singly stabilized enolate into an enamine so it can act as a michael donor and perform conjugate addition reactions
245
# chpt 21
How do you alkylate at both the alpha and beta positions using conjugate addition?
In the second step, before you protonate to form an enol you can react the alpha position to get a second alkylation
246
# chpt 9
What kind of bases are strong enough to deprotonate an alkyne?
N-, C-, H-
| NOT O-
247
# chpt 9
How do you prepare an alkyne?
double elimination using a geminal or vicinal dihalide
- 1st base can be anything
- 2nd base for 2nd elimination needs a strong base
248
# chpt 9
Mechansim for preparation of an alkyne
- elimination 1 (pt and LLG)
- elimination 2 (pt and LLG)
- pt to creat alkynide ion (if alkyne is terminal)
249
# chpt 9
What is the purpose of the deprotonating step at the end of preparing an alkyne?
it yields the most product
250
# chpt 9
Hydrohalogenation of Alkynes
| markovnikov
exs HX adds X to the more substitued position to get a dihalide
| 1 eq HX creates an alkene + 1 X at more sub positon
251
# chpt 9
Acid catalyzed Hydration of alkynes
| markovnikov addition
forms ketones with H2SO4 and HgSO4 via enol and ketone tautomerization
252
# chpt 9
Hydroboration Oxidation of Alkynes
anti markovnikov addition of OH and H yields aldehydes
253
# chpt 9
Alkylation of Alkynes
Strong base used to deprotonate alkynes to react with 1 or methyl akyl halides
254
# chpt 9
Catalytic Hydrogenation of Alkynes
H2 + metal catalyst = alkane
255
# chpt 9
H2 + Lindlars catalyst and a alkyne =
| Poisoned catalyst
cis alkene
256
# chpt 9
Na + NH3 (l) and an alkyne =
| dissolving metal reduction
trans alkene
257
# chpt 9
terminal alkyne + O3 and H2O =
a carb acid + CO2
258
# chpt 22
Amines can act as bases, nucleophiles, and acids but never as ---
eletrophiles
259
# chpt 22
Why are amines typically better bases than alcohols?
bc/ they are less electronegative so they don't dissociate in water
260
# chpt 22
True or false? Amines are only deprotonted in neutral and basic conditions
false, they are only deprotonated in basic conditions
261
# chpt 22
What are the four old ways we know to make amines?
1. reduction of NO2 on a benzene ring
2. reduction of amide w/ xs LAH
3. reduction of nitrile w/ xs LAH
4. EA with NH2
262
# chpt 22
What are the three new ways we know to make amines
1. Gabriel synthesis/ Potassium pthalimide
2. Azide synthesis
3. reduction amination
263
# chpt 22
Which of the three new ways can make 1, 2 and 3 amines?
reduction amination
264
# chpt 10
Heterolytic bond cleavage creates ---
ions
265
# chpt 10
homolytic bond cleavage forms ---
radicals
266
# chpt 10
stability of radicals
1< 2< 3< anything with resonance
| resonance trumps all
267
# chpt 10
What is an Intiation step for radicals?
creates the radical
| homolytic cleavage
268
# chpt 10
What is a propagation step for radicals?
electrons migrating around the the moleucle
| addition, abstraction, elimination
269
# chpt 10
What is a termination step for radicals?
an ending step that gets rid of the radical
| coupling
270
# chpt 10
halogenation of an alkane
Br2 + light = halogen at most stable position on alkane
271
# chpt 10
Allylic Bromination
NBS + heat = bromine on an allylic position
272
# chpt 10
Hydrohalogenation of an alkene
| anti markovnikov
HBr + ROOR = anti markovnikov addition of H and Br
273
# chpt 10
True or false? Radicals do not rearrange?
True
| unlike carbocations
274
# chpt 20
mechanism for fischer esterification
1. pt
2. nuc attack
3. pt
4. pt
5. LLG
6. pt
275
# chpt 20
reagents for a fischer esterification
carb acid + alcohol group and an acid catalyst
