Orgo I Flashcards
aromatic
alternating single and double bonds
delocalized pi conjugated system
nitrile
cyano
Carbon triple bonded to nitrogen
Formal charge
The difference between the number of electrons in an atom’s valence shell in its ground state and the number assigned
valence electrons- bonds- nonbonded electrons
epoxide
cyclic ether with a 3-atom ring
what are the steps of alcohol dehydration
protonation of an alcohol with water, water leaves and forms a carbocation, OH- attacks carbocation and forms alkene
Conformational isomers
when a molecule twists or rotates around its bond
known as a conformer
NOT TRUE ISOMERS- SAME exact molecule
enamine
secondary amine condensed with alkene
How can an alcohol form an alkene?
dehydration
ester
derived from an acid with hydroxyl replaced by an alkoxy group
Observed rotation
degree to which a sample rotates plane polarized light
What characteristics make up an Sn2 reaction
substitution, bimolecular
reaction rate depends of the concentration of two species
donor molecule
lewis base
Bases
abstract protons
full or partial negative charge
ketal
central carbon bonded to two -OR groups, two R groups
sp3d2
octahedral
square pyramidal
square planar
90°
meso compounds
molecules with two or more chiral centers that contain a plane of symmetry
epimers
differ only at one chiral center
by what mechanism is a 1° alcohol dehydrated?
E2
E/Z convention
Prioritize the two constituents on each carbon by molecular weight
E- two higher priority on opposite sides of the double bond
Z- two higher priority on the same side of the double bond
electrophiles
electron poor
partial or full positive charge
rotation of plane-polarized light
enantiomers rotate plane-polarized light
a triple bond has
one sigma and two pi bonds
heat of combustion
total energy released as heat when a substance undergoes complete combustion with oxygen under standard conditions
Huckel’s Rule
aromatic compounds must have exactly 4n+2 pi electrons
hydroxyl
-OH
polarimeter
apparatus that measures the rotation of plane-polarized light as it passes through a sample
racemic mixture
optically inactive mixture with 50:50 ratio of R:S
Do enantiomers contain a chiral center?
Yes
How many steps are in an Sn1 reaction?
two
what molecules does an Sn1 reaction favor?
poor nucleophiles, 3° carbons, polar protic solvents
are alcohols electro or nucleophilic?
nucleophilic
leaving groups
atoms or molecules that leave the parent molecule during a reaction
Relative configuration
spatial arrangement is identical but one non-identical substituent
-Ar is
benzene
Geometric isomers
cis/trans
Hybridization
mixing of atomic orbitals into new ones with different energies, shapes, etc suitable for the pairing of electrons to form chemical bonds
imine
contains a carbon nitrogen double bond
alcohol
organic compound with an -OH group
What characteristics make up an E1 reaction
elimination, unimolecular
reaction rate depends on the concentration of the reactant only
are meso compounds optically active?
no
nucleophiles
attach carbons and central atoms
full or partial negative charge
a single bond has
one sigma bond
Is alkane synthesis syn or anti addition?
syn
nitro
NO2
Acetyl
methyl group single bonded to a carbonyl
are nucleophiles a function of thermodynamics or kinetics?
kinetics
Do alcohols have a higher or lower BP/MP than alkanes? why?
higher, hydrogen bonding
How can the opening of an epoxide ring occur?
Sn1- protonation of O, opening of ring as the nucleophile attacks carbon, base abstracts proton
Sn2- nucleophile attacks carbon as the ring opens and the oxygen is protonated
Syn addition
two new bonds formed on the same side
Electronegativity of O
2.5
Pi bond
formed by side to side overlap of two p orbitals
what conformation of cyclohexane has zero ring strain
chair conformation
VESPR
Predicts the shape molecules will take due to the repulsion of lone pairs of electrons
grignard
R-MgBr
bond strength
measures of the energy required to completely break two atoms apart
what molecules does an E1 reaction favor?
weak bases, 3° carbons, polar protic solvents
Resonance
structures that are two forms of a molecule where the chemical connectivity is the same but the electrons are distributed differently around the structure
alkoxy
alkyl group single bonded to oxygen
R-O
How do R and S differ in the ways that they rotate plane polarized light?
same degree, opposite directions
MOM
methoxy-methyl ether
step 1 of an E2 reaction
abstraction of a proton by a base with the collapse of the electrons to an alkene and ejection of the leaving group
benzyl
benzene attached to a carbon
recipient molecule
lewis acid
protection of alcohols can be achieved with what?
trimethylsilyl ether (TMS) methoxy-methyl ether (MOM)
what direction to electrons flow?
negative to positive charge
bases/nucleophiles attach electrophiles
isomers
two molecules that have the same molecular formula but are different compounds
hydrazine
H2N-NH2
aliphatic
carbons form open chains
what are the products and reactants in a grignard synthesis?
carbonyl and grignard form an alcohol
vertical lines on a fischer projection
into the page
hemiacetal
acetal with one -OR group replaced with -OH
anomeric carbon
c-OH next to the oxygen of a ring
what alkanes have the highest melting points
straight chain
Dipole Moment
any time charge is not evenly distributed within a bond (nonequal electronegativities)
sp3d
trigonal bipyramidal seesaw T-shape Linear 120° and 90°
how can protecting groups be removed?
acidification
ether
r-o-r
aldehyde
organic compound containing formyl
Vinyl
ethylene with one H replaced by another atom (halogen)
mesyl
salt/ester of methanesulfuric acid H3C-SO3
anhydride
two acyl groups bonded to the same oxygen
Maximum optically active stereoisomers
2^n
n- number of chiral centers
Amine
derived from ammonia with hydrogen replaces by an organic group
How many steps are in an E1 reaction?
two
How can an alcohol be formed from a ketone or aldehyde?
reduce
acetal
central carbon bonded to two -OR groups, one R group and a hydrogen
step 1 of an E1 reaction
leaving group leaves, carbocation forms
Electronegativity
measure of the tendency of an atom to attract a bonding pair of electrons
Lowest electronegativity
Fr
sp2
trigonal planar
bent
120°
are arrows drawn towards or away from an electrophile?
towards
step 1 of an Sn1 reaction
dissociation of the leaving group forming a carbocation
specific rotation
observed rotation divided by length and concentration
-Ph is
benzene
levorotary
rotates plane polarized light counterclockwise
sp
linear
180°
does the BP/MP of an alkane increase or decrease with branching?
increase
what happens when you combine an alcohol with HCl?
formation of an alkyl halide
what are the reactants and products of the pinacol rearrangement?
vic-diol to an aldehyde or ketone
acid catalyzed
Exceptions to the octet rule
H/He stable with two valence electrons
B/Be stable with six valence electrons
Third period or higher stable with expanded octets
sp3
tetrahedral
trigonal pyramidal
bent
109.5°
Highest electronegativity
F
octet rule
atoms gain or lose electrons to obtain exactly 8 electrons in their valence shell
dextrorotary
rotates plane polarized light clockwise
How many steps are in an E2 reaction?
one
stereoisomers
same formula, same bond-to-bond connectivity, different in the 3D arrangement of the substituents
anti addition
two new bonds are formed on opposite sides
How many steps are in an Sn2 reaction?
one
axial
rise vertically
Structural isomers
same formula, different bond-to-bond connectivity
hemiketal
ketal with one -OR group replaced with -OH
what molecules does an Sn2 reaction favor?
good nucleophiles, 1/2° carbons
what are the steps of the pinacol rearrangement?
vic-diol plus acid protonates -OH to -OH2+ and water leaves forming a carbocation, methyl shifts are possible
resonance with the OH and carbocation to oxygen double bond and removal of H to a ketone or aldeyhde
name three reducing agents
NaBH4
LiAlH4
H2 and pressure
horizontal lines on a fischer projection
out of the page
Alkene
at least one c-c double bond
What happens when a 3° alcohol is combined with an oxidizing agent?
no reaction
Electronegativity of F
4
how do you synthesize an alkane from an alkene
H2 and a metal catalyst (Pd)
Which is stronger, a sigma or pi bond? why?
sigma bond because they have more overlap
actual structure
weighted average of all resonance contributors
more stable structures contribute more
Electronegativity of H
2.2
name three common oxidizing agents
O3 Cr2O7 CrO4 KMnO4 PCC PDC Collins Jones
are alcohols more or less acidic than water?
less
What happens when a 2° alcohol is combined with an oxidizing agent?
ketone
absolute configurations
R and S
assign priority to all substituents based on molecular weight, rotate lowest priority to the back
clockwise 1-3: R
counterclockwise 1-3: S
step 2 of an Sn1 reaction
attack of carbocation by the nucleophile
what can be used to reduce an acid or ester
LiAlH4
bonds broken and reformed via radical reaction
combustion
chiral center
atom attached to four different substituents
How does an alkyl halide form from an alcohol?
Sn2 or Sn1
add acid with halide to protonate alcohol, loss of -H2O and attack of carbocation or molecule by the halide to form alkyl halide
Allyl
methylene bridge attached to a vinyl group
-C6H5 is
benzene
what groups are electron donating?
negative
Alkyne
at least one c-c triple bond
TMS
trimethylsiyl ether
by what mechanism is a 2/3° alcohol dehydrated?
E1
What molecule reacts with an alcohol to form R-Cl
SOCl2
(+)
dextrorotary
Sigma Bond
Formed by head-on overlapping between atomic orbitals
Alkane
all c-c and c-h single bonds
vicinal
bonded to adjacent atoms
What happens when a 1° alcohol is combined with an oxidizing agent?
aldehyde, carboxylic acid
sulphone
SO2 attached to two carbons
Single bond is a
sigma bond
Amide
nitrogen single bonded to C of carbonyl
aromaticity
cyclic or planar molecule with a ring of resonance bonds that exhibits more stability than other geometric arrangements with the same set of atoms
Coordinate covalent bonds
both electrons shares in the bond are donated by one atom
anomers
differ only in their spatial orientation at the anomeric carbon of a ring
equatorial
extend horizontally
what does the opening of an epoxide form?
alcohol
what molecules does an E2 reaction favor?
strong or bulky bases
acyl
alkyl group with a carbon double bonded to oxygen
aryl
aromatic ring with one H removed
step 2 of an E1 reaction
base abstracts H from carbocation molecule and alkene forms
what are the steps in a grignard synthesis?
grignard attacks a carbonyl, acid donates a proton to O- forming an alcohol
does the BP/MP of an alkane increase or decrease with molecular weight?
increase
Geminal
bonded to the same atom
the second and third bonds between two elements are
pi bonds
step 1 of an Sn2 reaction
back side attack of the electrophile with simultaneous ejection of the leaving group
What characteristics make up an E2 reaction
elimination, bimolecular
reaction rate depends of the concentration of two species
ketone
carbonyl group bonded to two hydrocarbon groups
What groups are electron withdrawing?
positive
are bases a function of thermodynamics or kinetics?
thermodynamics
Enantiomers
stereoisomers that are non-identical, non-superimposable mirror images of one another
are alkenes electro or nucleophilic?
nucleophilic
tosyl
methyl group para substituted on benzene to SO3-R
Electronegativity of Fr
0.7
How is a tosylate/methylate formed?
tox/mes-Cl reacts with an alcohol, Cl- leaves and removes H from the molecule to form HCl and tos/mes-OR
carbonyl
carbon double bonded to oxygen
VESPR stands for
valence shell electron pair repulsion theory
valence
number of bonds an atom “normally” makes
Less stable bonds have ____ heats of combustion
higher
Carboxylic Acid
organic acid containing COOH
a double bond has
one sigma and one pi bond
Which atom is partially positive in a nitro group
nitrogen
(-)
levorotary
example of coordinate covalent
iron in hemoglobin
What molecule reacts with an alcohol to form R-Br
PBr3
Alkyl
hydrocarbon radical from removal of a hydrogen
dipole moment (u)=
charge*distance
distance between charges
What characteristics make up an Sn1 reaction
substitution, unimolecular
reaction rate depends on the concentration of the reactant only
Diastereomers
two molecules with the same formula and bond-to-bond connectivity that are non-identical but are not mirror images