Midterm 1 Review Flashcards
(95 cards)
1
Q
Penultimate carbon
A
Second to last carbon furthest away from aldehyde
2
Q
D-Glucose
A
When OH on penultimate carbon is on the right
3
Q
L-Glucose
A
When OH on penultimate carbon is on the left
4
Q
Anomeric carbon
A
Carbon bonded to oxygen and OH
5
Q
Alpha-anomer
A
When OH on anomeric carbon is axial
6
Q
Beta-anomer
A
When OH on anomeric carbon is equatorial
7
Q
Simple ylides give _ alkenes governed by ___
A
Z, kinetics
8
Q
Resonance-stabilized ylides give _ alkenes governed by ___
A
E, thermodynamics
9
Q
3 lines substituent
A
Propyl
10
Q
4 lines substituent
A
Butyl
11
Q
Substituent with 4 lines attached to one carbon
A
Tert-butyl
12
Q
IUPAC priorities
A
Aldehyde > ketone > hydroxy > alkene > alkyne > X, R, OR
13
Q
Simplest ketone
A
Acetone
14
Q
Simplest carbonyl
A
Formaldehyde
15
Q
Simplest aldehyde
A
Acetaldehyde
16
Q
Benzene ring attached to simple aldehyde
A
Benzaldehyde
17
Q
Benzene ring attached to simple ketone
A
Acetophenone
18
Q
Gilman reagent reactivity compared to grignard and organolithium reagents
A
Gilman reagent less reactive, more selective
19
Q
What reagent(s) would react with epoxides in the presence of acidic functional groups (-OH)?
A
Gilman reagents, not grignard or organolithium reagents
20
Q
___ pka predominates
A
Higher
21
Q
Carbocation: electrophile or nucleophile?
A
Electrophile
22
Q
Carbanion: electrophile or nucleophile?
A
Nucleophile
23
Q
Grignard reagents: strong or weak bases?
A
Strong
24
Q
Organolithium reagents: strong or weak bases?
A
Strong
25
Gilman reagents: strong or weak bases?
Weak
26
Trans alkene + reagents: CH2I2 Zn(Cu)
Triangle forms where double bond was with anti substituents (one wedge one dash), racemic
27
Cis alkene + reagents: CH2I2 Zn(Cu)
Triangle forms where double bond was, triangle arms are syn racemic (both wedge or both dash)
28
Grignard reagent reaction with an epoxide mechanism
C-MgBr bond attacks least substituted carbon, that carbon’s bond to O breaks off O
Arrow label: attack of the nu
Product 2: O shifts over with additional lone pair (now 3) and - charge, substituent excluding MgBr added, MgBr with + charge byproduct, a lone pair on O attacks a proton from given acid whose bond breaks off of its O
Arrow label: add a proton
Product 3: H replaces one of three lone pairs (now neutrally charged), H2O byproduct
29
What is special about grignard reagent reaction with an achiral meso epoxide?
Achiral meso epoxides are symmetrical, substituent-MgBr can attack from either side, 2 racemic products
30
Grignard (or organolithium) reagent with an aldehyde or a ketone mechanism
C-MgBr bond attacks carbonyl carbon, that carbon’s bond to O breaks off O
Arrow label: attack of the nu
Product 2: O gains a lone pair (now 3) and - charge and now on a single bond, substituent excluding MgBr now on other side of ex-carbonyl carbon, MgBr with + charge byproduct, a lone pair on O attacks a proton from given acid whose bond breaks off of its O
Arrow label: add a proton
Product 3: H replaces one of three lone pairs (now neutrally charged), H2O byproduct, OH can be on a wedge or dash (racemic)
31
Key recognition element: -OH group and the new carbon-nucleophile are on the same carbon
Grignard (or organolithium) reagent with an aldehyde or a ketone
32
How can you make a carboxylic acid with a Grignard reagent?
CO2
33
Alkyne anion reacting with an aldehyde or ketone mechanism
Lone pair on deprotonated alkyne attacks carbonyl carbon, that carbon’s bond to O breaks off O
Arrow label: attack of the nu
Product 2: O gains a lone pair (now 3) and - charge and now on a single bond, substituent (- charge and lone pair went away) now on other side of electrophilic carbon bound by a wedge or dash (racemic), Na+ byproduct, a lone pair on O attacks a proton from given acid whose bond breaks off of its O
Arrow label: add a proton
Product 3: H replaces one of three lone pairs (now neutrally charged), H2O byproduct, product remains racemic
34
HCN reacting with an aldehyde or ketone mechanism
Lone pair on deprotonated carbon attacks carbonyl carbon, that carbon’s bond to O breaks off O
Arrow label: attack of the nu
Product 2: O gains a lone pair (now 3) and - charge and now on a single bond, C (- charge and lone pair went away) triple-bonded to N now on other side of electrophilic carbon, a lone pair on O attacks a proton from given acid whose bond breaks off of its bonded atom
Arrow label: add a proton
Product 3: H replaces one of three lone pairs (now neutrally charged), C (with lone pair and - charge) triple-bonded to N byproduct, OH could be on a wedge and H on electrophilic carbon would be on a dash or vice versa (racemic)
35
After HCN reacting with an aldehyde or ketone mechanism, what happens when you react H2/Ni OR LiAlH4 and H2O?
N becomes NH2, product remains racemic
36
The Wittig reaction with simple ylide mechanism
Ph3P’s lone pair on P attacks carbon on haloalkane, carbon’s bond breaks off LG atom
Arrow label: simultaneous attack of the nu and departure of the LG
Product 2: Ph3P+ replaces LG and one H on C is suggestively drawn, LG now with four lone pairs and - charge byproduct, lone pair on deprotonated base attacks suggestively drawn H whose bond with C breaks
Arrow label: remove a proton
Product 3: suggestively drawn H goes away and C gains a lone pair and - charge, Li+ byproduct, resonates to Ph3P=CH2
37
The Wittig reaction with resonance-stabilized ylide mechanism
Lone pair on C attached to Ph3P attacks carbon on resonance-stabilized ylide, carbon’s bond breaks off O
Arrow label: attack of the nu
Product 2: O gains a lone pair and - charge and now single-bonded to C
Arrow label: n/a
Product 3: resonates, bond between C and O points to O, O loses a lone pair and forms a bond with Ph3P (both become neutrally charged), bond between Ph3P and CH2 points to bond between that CH2 and the electrophilic carbon
Arrow label: n/a
Product 4: O- bonded to Ph3P+ leave, double bond forms between electrophilic carbon and CH2
38
Acid catalyzed hemiacetal and acetal formation from an aldehyde and ketone mechanism
Lone pair on carbonyl oxygen attacks an H, which breaks off O
Arrow label: add a proton
Product 2: byproduct and major product form. Carbonyl double bond points to carbonyl O and resonates to give O a lone pair. Lone pair on nucleophile attacks carbocation.
Arrow label: attack of the nu
Product 3: major product forms, lone pair on given base removes an H from ex-nucleophile
Arrow label: remove a proton
Product 4 (hemiacetal intermediate): byproduct and major product form, lone pair on O from carbonyl steals a proton
Arrow label: add a proton
Product 5: byproduct and major product form, arrow drawn for H2O LG to leave
Arrow label: departure of the LG
Product 6: H2O leaves, + charge where LG broke off, O lone pair points to its bond with carbocation, resonates to double bond and + charge moves to O, lone pair on new given nucleophile attacks ex-carbocation which breaks off the O it is double-bonded to
Arrow label: attack of the nu
Product 7: major product forms, given base steals proton from newly-added nucleophile
Arrow label: remove a proton
Product 8: byproduct and major product form
39
Why no SN2 (attack of nu rather than remove a proton) in the last step of acid catalyzed hemiacetal and acetal formation from an aldehyde and ketone?
Because of sterics
40
Acid catalyzed formation of cyclic hemiacetal mechanism
Electrophilic oxygen steals proton
Arrow label: add a proton
Product 2: byproduct and major product form, lone pair on OH (not double-bonded) attacks more electrophilic carbon, one of the double bonds goes back to oxygen
Arrow label: attack of the nu
Product 3: ring forms, given base removes a proton
Arrow label: remove a proton
Product 4: byproduct and major product form, racemic about OH (where the double bond O was)
41
Base-catalyzed formation of a hemiacetal mechanism
Lone pair on base removes a proton attached to O
Arrow label: remove a proton
Product 2: byproduct and major product form, deprotonated oxygen attacks given electrophilic carbon, double bond gives oxygen a lone pair
Arrow label: attack of the nu
Product 3: O- attacks given proton
Arrow label: add a proton
Product 4: byproduct and major product form, asterisk on chiral center
42
Carbon radical: electrophile or nucleophile?
Electrophile
43
Carbene: electrophile or nucleophile?
Both
44
Primary OH + PCC
Aldehyde
45
Secondary OH + PCC or H2CrO4
Ketone
46
Alkene + 1) O3
2) (CH3)2S
Ozonolysis
47
Terminal alkyne + 1) (sia)2BH
2) H2O2, NaOH
Aldehyde on terminal carbon, carbon chain of single bonds
48
Terminal alkyne + HgSO4
H2SO4, H2O
Ketone on internal (most substituted) carbon from alkyne, carbon chain of single bonds
49
Alkene + 1) BH3
2) H2O2, NaOH
Non-Markovnikov OH
50
Alkene + H2O (or ROH)
Cat H2SO4
Markovnikov OH (or -OR)
51
Alkene + 1) Hg(OAc)2, H2O
2) NaBH4
Racemic Markovnikov OH
52
Alkene + HBr
Markovnikov Br
53
Alkene + Br2
Br on both carbons, racemic anti product
54
Br on both carbons racemic anti product + 1) 3NaNH2
2) H3O+
Brs go away and in between those, an alkyne forms
55
Alkene + 1) OsO4
2) NaHSO3
OH on both carbons, racemic syn product
56
Alkene + H2/Pd
Alkane syn product
57
Alkene + Br2
H2O
OH on the most substituted carbon, Br on the least substituted carbon, racemic anti product
58
OH on the most substituted carbon Br on the least substituted carbon racemic anti product + NaOH
Racemic syn epoxide
59
Alkene + RCO3H
mCPBA
Racemic syn epoxide
60
Alkene + NBS, hv
Double bond moves away one to be more stable, Br adds to least substituted carbon (allylic bromoalkene)
61
Alkene + HBr
H2O2
Non-Markovnikov Br
62
Alkene + 1) OsO4
2) NaHSO3
OH on both carbons, racemic syn product
63
Br on both carbons racemic anti product + 3NaNH2
Brs go away and in between those, a deprotonated alkyne forms
64
Internal alkyne + H2
Lindlar
Cis alkene
65
Internal alkyne + Na°
NH3
Trans alkene
66
Carbon chain of single bonds with primary Br + E2
tBuOK
Br goes away, double bond forms between the carbon Br was connected to and the carbon next to it
67
Secondary or tertiary Br + tBuOK
E2
Br goes away, double bond forms between the carbon Br was connected to and the least substituted carbon (non-Zaitsev)
68
Secondary Br + E2
NaOH
Br goes away, double bond forms between the carbon Br was connected to and the most substituted carbon
69
Primary Br + NH3
SN2
NH2 substitutes Br
70
Primary OH + PBr3
SN2
Br substitutes OH
71
Secondary OH + SOCl2
pyridine
Cl substitutes OH and stereochemistry inverted
72
Tertiary OH + HBr
SN2
Br substitutes OH
73
Primary OH + conc H2SO4
E2
OH goes away, double bond forms between the carbon OH was connected to and the carbon next to it *double bond could resonate to be more stable
74
Primary OH + H2CrO4
Double bond O added to carbon next door to OH
75
Syn epoxide + NH3
NH2 added to least substituted carbon in an anti fashion, O from epoxide becomes OH and retains stereochemistry
76
Syn epoxide + NaOH
OH added to least substituted carbon in an anti fashion, O from epoxide becomes OH and retains stereochemistry
77
Syn epoxide + NaOCH3
OCH3 added to least substituted carbon in an anti fashion, O from epoxide becomes OH and retains stereochemistry
78
Syn epoxide + NaCN
CN added to least substituted carbon in an anti fashion, O from epoxide becomes OH and retains stereochemistry
79
Syn epoxide + 1) LiAlH4
2) H3O+
H added to least substituted carbon in an anti fashion, O from epoxide becomes OH and retains stereochemistry
80
Syn epoxide + NaN3
N3 added to least substituted carbon in an anti fashion, O from epoxide becomes OH and retains stereochemistry
81
Syn epoxide + 1) RC [triple bond] C : -
2) H3O+
Substituent added to least substituted carbon in an anti fashion, O from epoxide becomes OH and retains stereochemistry
82
Syn epoxide + 1) C-C-MgBr
2) H3O+
Ethyl added to least substituted carbon in an anti fashion, O from epoxide becomes OH and retains stereochemistry
83
Syn epoxide + CH3OH
Cat H2SO4
O from epoxide becomes OH on least substituted carbon and retains stereochemistry, OCH3 added to most substituted carbon in an anti fashion, methyl on most substituted carbon gets its stereochemistry inverted
84
Syn epoxide + H2O
Cat H2SO4
O from epoxide becomes OH on least substituted carbon and retains stereochemistry, OH added to most substituted carbon in an anti fashion, methyl on most substituted carbon gets its stereochemistry inverted
85
Br on both carbons racemic anti product + 2NaNH2
Internal alkyne
86
Alkane + Br2
hv or heat
Br added to most substituted carbon
87
Alkene + HBr
ROOR hv or heat
Br added to least substituted carbon of double bond, and double bond goes away
88
Secondary OH + H2SO4
Double bond forms between carbon OH was attached to and the carbon next to it, OH goes away
89
Key recognition element: what does the formation of a carbon-carbon double bond mean?
Wittig Reaction
90
Primary Br + 1) Ph3P
2) butylLi
+PPh3 substitutes Br, lone pair and - charge on the carbon next to it
91
Carbonyl reactant + H2O <-> hydrate product
Which side predominates?
Side with less sterics predominates
92
When Fs are present in carbonyl reactant + H2O <-> hydrate product, which side predominates?
Product side predominates because carbonyl carbon is more electrophilic and inductive effects
93
What reagents do Grignard reagents react with?
Epoxides, aldehydes/ketones
94
What reagents do organolithium reagents react with?
Epoxides, aldehydes/ketones
95
What reagents do Gilman reagents react with?
Epoxides, 1° and 2° alkyl halide
