MCAT Organic Chemistry Terms Flashcards

Terms Definitions
(aka 2-propanone)
m-chloroperoxybenzoic acid
Oxidation of Aldehyde
a functional group
name for mathanal
aprotic solvent
not solvated
name for propanal
5C sugar, ex: fructose
1° Alcohol with K₂Cr₂O₇
acyl chloride
(aka acid chloride)
ketone carbohydrates like fructose
F, CL, Br, I
not ignored
iso, neo, cyclo
like amylopectin but in animals
pka list of acids
HCl........................ -2.2
Acetic Acid ..............4.8
Water ......................15.7
Ethanol ...................15.9
t-butyl Alcohol ........18
- Nitrogen containing compounds:
1. may act as a L-B donating their lone pair e'
2. may act as a nuke where the lone pair of e' attacks a + charge
3. Nitrogen can take on a 4th bond = become +
- ammonia and amines act as weak bases by donating their lone pair e's
- EW substituents ⬇ bacicity of an amine
- ED substituents ⬆
- But, steric hinderance created by bulky functional groups hinder the ability of an amine to donate its lone e' pair
∴ 2° > 1° > ammonia
production of soap from triacylglycerols cleaved by the addition of NaOH
IR spectroscopy
(infrared spectroscopy) records frequencies of bonds to identify functional groups in compounds
refers to the =CH2 group
di, tri, t, sec, n-
zn/h or CH3/s with ozonolysis
6 bonds at 90° and 90°
reactions type that needs less substituted substrate and strong nucleophile
Ketone with C₆H₅CO₃H
C₆H₅CO₃H has excessive O; Ketone reactant is being oxidized
bond dipole moment
dipoles within a bond
resolution (separation) of a mixture by passing it over or through a matrix that adsorbs different compounds with different affinities, ultimately altering the rate at which they lose contact with the resolving matrix
when a carboxylic acid loses CO2
chiral center
carbon with four different substituents and lack a plane of symmetry
anti conformation
most favorable of staggared conformations
one s and three p orbitals
non mirror image of configurational isomers. cis and trans alkenes are them. possible when a molecule has two or more stereogenic centers that differ at some but not alll of the centers. they require multiple chiral centers.
creation of long, high molecular weight polymer composed of repeating subunit called monomers. occur through a radical mechanism.
carbonyl located in middle or somewhere in chane. Named with ONE
What direction does the s configuration take priority?
glu+glu, alpha 1-4 equitorial O bond polymer
Saytzeff Rule
rule that the most substitituted alkene is the major product
reaction type that needs a strong base
Halogenation process
Initial Final
1. Initiation 0 2
2. Propagation 1 1
3. Termination 2 0
- exothermic process ∴ releases energy from the system
- stability : 3° > 2° > 1° > methyl
- order of reactivity = F, Cl, Br, I
- F can be so explosive b/c it's so reactive, while I won't react
- Br requires heat to react (more selective than Cl and F)
F most likely 1° would dominate
Cl most likely 2° would dominate
Br most likely 3° would dominate
Hybridization / Bond angle / Shape relationship
sp²----120---Trigonal planar
sp³----109.5--tetrahedral, pyramidal, or bent
dsp³---90, 120-trig-bypyram., seesaw, t-shaped, line
d²sp³---90---octahedral, sq. pyramidal, sq. planar
diastereomers that differ at only one chiral carbon
alkane reaction with oxygen creating a violent reaction; energy must be added as heat for example
two unique molecules with the same molecular formula and the same bond-to-bond connectivity; enantiomers and diasteriomers
structural isomers
share molecular formula but have different chemical and physical properties
relative configuration
configuration in relation to another chiral molecule. use it to determine if a molecule is an enantiomer, diastereomer, etc
peroxycarboxylic acid
alkene oxidized with this, strong oxidizing agent. CH3CO3H or mcpba and it makes epoxide or oxirane
geometric isomers
differ in position of substitutents attached to a double bond or cycloalkane. Cis or trans or e or z
ring strain
arise from angle strain, torsional strian and nonbonded strain
protic solvent
solvents with protons in solution, e.g. water or alcohol. large atoms tend to be better nucleophiles in here because they can shed the solvating protons around them and are more polarizable
formed by mixing different types of orbitals
like maltose but has alpha 1,6 glucose branches every 24-30 units, found in plants
NaBH₄ and LiAlH₄
- Reducing agents
NaBH₄ can reduce: Aldehydes, Ketones
LiAlH₄ can reduce: Aldehydes, Ketones, Esters, Acetates
- Al is less electronegative than B so LiAlH₄ is more apt to donate an H- to the carbonyl carbon, and thus is more reactive than NaBH₄
- have the same molecular formula
- same bond to bond connectivity
- NOT mirror images
- NOT the same compound
- One special type = geometric isomer
anomeric carbon
the only carbon attached to two oxygens on a carbohydrate ring; carbon where a chiral center is when anomers form
plane-polarized light
light that consists of photons and their electric fields oriented in the same direction
common name for a 6 carbon aldehyde carbohydrate like glucose
parent peak
peaks made by ions in mass spectrometry
observed rotation
direction and degree to which a compound rotates plane-polarized light
electron donating groups direct to which position(s)?
ortho and para
hydration of an alkene
electrophilic addition reaction in which an alkene becomes an alcohol in the presence of an acid
angle strain
when bond angles deviate from ideal values
carbonyl located at the end of the chain named by replacing al with e. e.g. butanal
a radical transfers a hydrogen atom to another radical and makes an alkane and alkene
catalytic hydrogenation
reducing an alkene by adding molecular hydrogen to double bond with aid of metal catalyst. e.g. pt, pd, ni. takes place on surface of metal so it does syn addition
specific rotation
a = observed rotation / concentration * length
Markovkikov's Rule
rule that hydrogen adds to the least substituted carbon on an alkene
Pinacol Mechanism
- 1st hydroxyl group is protonated and removed by the acid to form a C+
- methyl group may move to form a more stable C+ (exhibits resonance)
- Water deprotonates forming pinacolone and regenerating the acid catalyst.
- sp³ = 109.5°
- Ring strain = zero for cyclohexane and ⬆ as rings become smaller or larger
Absolute configuration
- all 4 substituents differ around a chiral carbon
diazonium ion
created from a 1° amine using the nitrosonium ion; it can be used to make a variety of other groups
two p orbital form pi and third p orbital combine with s to make two sp hybrid. 180 degree apart
primary carbon
is bonded to only one other carbon atom
pi bond
when two p orbitals line up in parallel and electron clouds overlap. it exsits over a single bond.
index of H deficiency
number of hydrogen pairs to become saturated, equal to [(2n+2) ーx] /2
Wolff Kishner Reduction
- reduce a ketone or aldehyde by removing oxygen and replacing with two hydrogens in a base
- you can do the same thing by adding hot acid to a ketone or aldehyde, but some ketones and aldehydes can't survive the hot acid
∴ W-K reduction
heat of combustion
- Δ H of a combustion reaction
⬆ heat of combustion ⬆ energy level of the molecule ∴ less stable
Alkane nomenclature
Use the Greek root for the number of carbons followed by the ending, -ane
What are constitutional isomers?
Isomers whose atoms have a different connectivity.
Order of Amine selectivity
2° > 1° > ammonia
- Aromatic amines (amines attached to a benzene ring) are much weaker bases b/c e' pair con be delocalized around the benzene ring
- substituents that withdraw e's from the benzene ring will further weaken the aromatic amine
peptide bond
bond between the N and C in an amide; strings together amino acids to make polypeptides
index of hydrogen deficiency
the number of pairs of hydrogens a compound requires in order to become a saturated alkane
How many electrons does an aromatic ring have?
4n+2 electrons in pi orbitals
Physical properties of Carboxylic Acids
- able to make strong double H-bonds to form a dimer
- ⬆ BP of C.A. by doubling MW
- C.A. with...
4 ≤ carbons are miscible in water
5 + carbons are increasingly less soluble in water
10 + carbons are insoluble in water
- C.A. are soluble in most nonpolar solvents b/c the dimer from allows the C.A. to solvate w/out disrupting the H-Bonds of the dimer
max number of optically active isomers that a single compound can have
n = number of chiral centers
What happens when electrons move closer to a positive charge
- they lower their energy level.
- it would require energy input to separate opposite charges
- system with low energy = stable
∴ bond formed when electron energy is the lowest
What must happen for a molecule to have chirality?
It must have asymmetric carbons (chiral centers) without an internal mirror image. Compounds with an internal mirror image are meso compounds.
C3H8 + 5O2 = 3CO2 + 4H2O + heat
combustion reaction occurs through a radical process
Why is it more difficult to reduce esters and acetates than ketones and aldehydes?
- Because the group attached to the carbonyl of the ester or acetate is a stronger ED than an alkyl group or H.
- By donating e' more strongly, it ⬇ the + charge on the C=O making it less attractive to the nuke.
/ 97

Leave a Comment ({[ getComments().length ]})

Comments ({[ getComments().length ]})


{[ comment.comment ]}

View All {[ getComments().length ]} Comments
Ask a homework question - tutors are online