OAT Organic Chemistry
Racemization
*loss of optical activity* that occurs when reaction shows neither clean retention of configuration nor clean inversion of configuration
Intermolecular forces in Extraction
- "like dissolves like" - "like attracts like"
bond order
- # of bonds between atoms: 1 for single bond 2 for double bond 3 for triple bond - # of electron pairs being shared by given pair of atoms - # of shared electron pairs between two atoms - Example: Nitrous Oxide (N triple bond N single bond O) Bond Order between Nitrogens depends on resonances (3 + 2 + 1) / 3 = 6 / 3 = 2
Hydroboration
- *anti-markovnikov syn hydration addition* - BH3 or B3H6 used - HOOH (or derivative) used - reduce a bond: 1. triple bond to double bond 2. double bond to single bond
Nucleophiles of SN1 reaction
- *weak* (or strong); doesn't matter b/c carbocation is OPEN! - Examples: H2O NH3
SN1 reactions
- 1st order - intermediate = carbocation - carbocation follows 3* > 2* > 1* - polar protic solvents stabilize carbocation by h-bonding - if substrate is optically active, racemic mixture results
stereochemistry of E1 elimination
- 2 products possible - Zaitsev Rule: most substituted product is favored
Free Radical Reactions
- 3 steps 1. initiation 2. chain propagation 3. chain termination
sp3 hybridized
- 4 sigma (single) bonds - bond angle: 109.5*
Solvents of SN2 reaction
- APROTIC! - Examples: Acetone Dimethyl Sulfoxide (DMSO)
Stereochemistry of E2 elimination
- Anti-periplanar - staggered
Friedel-crafts acylation
- Aromatic ring acylated through electrophillic aromatic substitution - AlCl3 = lewis *acid* catalyst
Examples of Aldehydes
- Butanal - p-Nitrobenzene carboxaldehyde
sp hybridized
- C atom participating in a single & triple bond - 4 sigma bonds & pi bonds - bond angle: 180*
sharp IR peak around 1725 cm-
- Carbonyl (C=O) bond - could be aldehyde, carboxylic acid, or ketone [IR spectra]
Factors that increase melting point
- H-bonds - hydroxyl groups - polar carbonyl bonds - dipole moments - longer chains
Hydrogenation Reaction
- Hydrogen is added to molecule - occurs in presence of metal catalyst (Pt, Ni, Pd)
reducing agents
- LiAlH4 - H+ / H2O
E2 and SN2
- NO carbocation - polar aprotic solvent used
Substrates of E2 elimination
- Primary, secondary, or tertiary - NOT methyl (CH3) ; NO second C for double bond
SN2 vs. E2
- SN2 & E2 occur competitively - SN2 inhibited by highly substituted substrates & bulky bases
Conformational Isomers
- Stereoisomers - differ by rotation about one or more single bonds - diff. rotation around single sigma bond - Any compounds that have same molecular formula & same connectivity but differ from one another by rotation about sigma bond
Protic Solvent
- able to form H-bonds - able to donate H+ - forms H-bonds with LG so it stays away / gone
Examples of Ketones
- acetone - phenylethanone
superimposable compound
- achiral - can contain chiral centers, but overall achiral - optically inactive - possesses internal plane of symmetry - Example: meso compound
Electron Donating Groups
- activating - ortho / para directing 1. OH (hydroxyl) 2. NH2 (amino) 3. alkyl
Carbonyls
- aldehydes - ketones
Single proton single H NMR signal
- all protons are in identical chemical environments - all protons are equivalent - have same chemical shift - same relative positions
diastereomers
- any stereoisomer that is not an enantiomer - stereoisomers that are NOT mirror images of each other - differ at one or more chiral centers, but NOT all chiral centers - can be separate from one another bc they do NOT have small physical properties as one another - distillation & recrystallization are effective techniques - Examples: epimers meso compound
Solvents of E2 elimination
- aprotic solvent would be best - often conjugate acid of strong base is used
Dispersion forces
- arise as random fluctuations in electrons density of molecule - induce transient / brief dipoles in nearby molecules - leads to electrostatic attraction between two molecules - forces increase as surface area of molecule increases
Straight-Chain Alkanes
- as molecular weight increases, dispersion forces between molecules become stronger - as molecular weight increases, chain becomes longer & longer - as molecular weight increases, size / surface area increases - BP increases as chain becomes longer
Separate mixture of compounds
- based on one of two factors: 1. solubility 2. reactivity
Free Radical Initiation
- bond is cleaved homolitically (promoted by heat / uv light) to produce free radicals - end thermic (system must absorb E)
Reverse aldol reaction
- breaks bonds between alpha & beta carbons of molecule - alpha & beta carbons are the first & second carbons away from carbonyl carbon - products (1 of the 3 choices): 1. two aldehydes 2. two ketones 3. one aldehyde & one ketone
Ester Grignard reaction
- can do 2+ rounds of Grignard reagents (if there is excess) - can get a very large compound / molecule
E1 and SN1
- carbocation is stable if LG dissociates - protic solvent used
Anomeric Carbon
- carbon directly bonded to 2 oxygen atoms - most reactive carbon
Stereospecific Reduction / Hydrogenation
- catalyzed by H2 & palladium (Pd), Nickel (Ni), Platinum (Pt), some metal - results in addition of 2 Hydrogen atoms on same side of molecule = "syn-addition" - puts methyl & ethyl substituents on same side of double bond = "cis isomer" is formed - Hydrogen is added to molecule - occurs in presence of metal catalyst (Pt, Ni, Pd)
Peroxide
- causes free radical - Examples: O2 2- HOOH
acidity
- chemical characteristic that helps determine how a substance dissolved in water will interact w/ & affect its environment - dependent upon induction & resonance effects - electron-withdrawing groups absorb negative charge = increase in acidity - electron-donating groups donate additional electron density & destabilize negative charge = decreasing acidity - most acidic: 1. molecule will have acidic hydrogen 2. molecule w/ most electron-withdrawing groups 3. molecule with fewest electron-donating groups 4. resonance
separation of enantiomers
- chemically alter molecules so they are different from one another - react each enantiomer with same chiral molecule in addition reaction to yield two diastereomers
Friedel-crafts acylation of phenol
- chloride is removed - acyl carbonyl C forms bond to aromatic ring - intermediate of acyl group is already stabilized after Cl leaves due to double bond on oxygen (thus, will not rearrange for greater stability) - OH group on phenol ring is O/P directing - AlCl3 = lewis acid catalyst
homolysis
- cleavage of covalent bonds in which each fragment departs w/ one of the electrons of the covalent bond that joined them - fragments = "radicals" - produces radical pair - bond cleavage in which both atoms contain one electron - promoted by heat / uv light
Quaternary Ammonium salt
- contains Nitrogen atom that is bonded to 4 groups - Nitrogen has formal charge of +1 - nitrogen-containing compound interacts ionically with negative ion
Electron w/drawing
- deactivating - meta directing: 1. NO2 2. Carbonyl - ortho/para directing: 1. halogens
SN1 reaction
- deadbeat LG packs up its electrons & leaves - carbocation is left alone & must be strong & stable - R groups = friends & family that support carbocation in time of need - Hot new Nu rushes in & creates a new & better relationship
Bases of E1 elimination
- does NOT require strong base - Example: H2O
Bronsted-Lowry Acids
- donate protons (H+) - form conjugate bases upon deprotonation - Examples: CH3CH2COOH HCl HCOOH HNO3
Sigma bond
- end-to-end overlap of 2 hybridized orbitals - single bond that exists between every covalently bonded set of atoms
Derivatives of Carboxylic acids
- esters - acyl chlorides - acid anhydrides - alcohols - alkanoyl halide - amides
Separation Methods
- extraction (using separation funnel) - distillation
Less Substituted
- fewer R groups have more H's around double bond - minor product
Production of Ether
- general formula ROR - oxygen connects 2 carbons together 1. condensation of 2 alcohols - simplest production involves removing water from two alcohols 2. Reaction of Metal Alkoxide ions with primary alkyl halides - metal alkoxide ions have oxygen w/ negative charge that easily attacks methyl halide 3. Oxidation of alkene w/ proxy acid (RCOOOH) - alkenes that are reacted w/ proxy acids lead to cyclic product (in place of double bonds)
Leaving Group of SN1 reaction
- good LG is stable alone - Example: Halogens OH
Leaving Groups of E1 elimination
- good LG required - Example: Halogens (Br-)
Leaving Groups of SN2 reaction
- good LG required - Example: Halogens (Cl-)
Leaving groups of E2 elimination
- good LG required - example: Halogens (Br-)
Radicals
- have unpaired electrons - highly reactive - formed by UV light (hv), heat, OR peroxides (RO-OR [or] HO-OH) - goes on MOST substituted carbon - form w/ Cl- or Br- ONLY
anti-bonding molecular orbitals
- higher in energy than corresponding bonding molecular orbitals - less stable than corresponding bonding orbital - the higher the energy of a given molecule or atom, the lower their stability - occur when electron wave functions of two electrons overlap in destructive pattern - formed when signs of wave functions of two atomic orbitals are NOT the same - when wave functions add destructively, there is smaller chance of finding electron in that orbital compared to when they add constructively - can be found in both diatomic & polyatomic molecules - formation is NOT limited by number of atoms present in compound - electron density is likely low in these regions
Zaitsev's rule
- in B-elimination reaction, most highly substituted alkene will be major product - most substituted alkene is major product of Elimination reactions
Mass Spectrometry
- info about molecular weight - technique that separates particles according to their mass - ionization patterns are used
multivalent ion
- ion w/o constant charge - Examples: Fe^2+ Fe^3+
Conformational isomers
- isomers that can introverted through rotations about single bonds - Example: chair & boat conformations of cyclohexane
Keto-enol tautomerism
- ketone w/ alpha hydrogens exists in equilibrium with enol - equilibrium heavily favors ketone form, typically - special constitutional (structural) isomerism
High Boiling Point characteristics
- longer & least branched compound - longer the alkane = more it weighs = more difficult to "push" molecule into gas phase - longer alkanes experience stronger van der waals forces - electrons can localize on one end of chain more easily - straight chain alkanes
C NMR
- measure amount of electric field absorption & reflection of C nucleus - tells about molecule's Carbon backbone
H NMR
- measures amount of electric field absorption & reflection of H nucleus - using data about H+ to determine molecule's carbon backbone
pyrolysis
- mechanism breaks longer carbon chains into shorter alkyl radicals (ie: methyl radicals & ethyl radical) - after formation, these alkyl radicals can bind to each other & reform into both smaller & larger alkane chains (ie: ethane & butane)
racemic mixture
- mixture of equal amounts of enantiomers - mixture that contains equal amounts of (+) & (-) enantiomers - NOT optically active
More substituted
- more R groups, fewer H's around double bond - major product
zwitterion
- neutral ion / species / molecule that has both negative & positive charge
Properties that stabilize SN2
- non polar solvent - doesn't interfere with Nucleophile attacking substrate - stabilize ionic (charged) intermediate - higher concentration of nucleophile affects reaction kinetics
Enantiomers
- non-superimposable mirror images - configuration of each molecule at each chiral center is diff. - have equal & opposite specific rotations at each chiral center - same general structure - same atoms - same connectivity - same physical properties (mass, BP, MP, pKa..) - diff. arrangments around chiral center
cis-trans isomerism
- occurs in alkenes - describes arrangement of substituents across double bond - special type of E/Z isomerism in which there is non-hydrogen group & H atom on each C of a C double bond
sp2 hybridized
- one double bond & two single bonds - 3 sigma bonds - 1 pi bond - bond angle: 120*
Achiral
- optically inactive - molecule that is superimposable on its mirror image
Halogens
- ortho/para-directing ring deactivators
Acid Anhydride
- oxide that forms an acid when reacted w water - two acid molecules that are linked with an ester-like bond with loss of water - very reactive - will regenerate acids used to form them when water is added
Properties that stabilize SN1
- polar protic solvents - substituted substrates - weak nucleophiles - Nu- have a hard time displacing LG - THUS favoring formation of carbocation intermediate before nucleophilic attack - reaction kinetics = independent of nucleophile concentration
Anode
- positive terminal of electrophoresis - amino acid that possesses net negative charge will migrate here - Positively charged electrode
Benzoic Acid
- primary alcohol - cannot be further oxidized regardless of agent used
2-methylpropanol
- primary alcohol - when reacted with sodium dichromate (Na2Cr2O7) & sulfuric acid (H2SO4), will become carboxylic acid
2-phenylethanol
- primary alcohol - when reacted with sodium dichromate (Na2Cr2O7) & sulfuric acid (H2SO4), will become carboxylic acid
Benzyl Alcohol
- primary alcohol - when reacted with sodium dichromate (Na2Cr2O7) & sulfuric acid (H2SO4), will become carboxylic acid
induction
- process by which electronegative electron-withdrawing group stabilizes negative charge - the closer & more electronegative the group, the greater the effect, the more stable the conjugate base, the stronger the acid - electronegative group close to acidic hydrogen
Grignard Reaction
- products are ALWAYS alcohols
Solvents of SN1 reaction
- protic solvent - Example: acid
Aldol Condensation
- reaction in which aldehyde or ketone acts as both electrophile & nucleophile - resulting in formation of new C-C bond in new molecule called "aldol" - can be: 1. Aldehyde + Aldehyde 2. Ketone + Ketone 3. Aldehyde + Ketone - Catalyzed by acid or base - Aldol is unstable & is easily dehydrated by heat or base
Sodium Borohydride
- reducing agent
SN2
- requires good nucleophile - does not necessarily require strong base - requires clear access to substrate opposite the leaving group
E2
- requires strong, bulky base to attack substrate - Heat + Base =
optically active
- rotates the plane of polarized light - compound that is asymmetrical & chiral
Structural / constitutional isomers
- same molecular formula, diff. connectivity / diff. bonds between atoms / diff. bonding sequence - can have many diff. physical & chemical properties - same #s & types of atoms are present but bonded to one another differently - wide variations in chemical & physical properties
1-phenylethanol
- secondary alcohol - when reacted with sodium dichromate (Na2Cr2O7) & sulfuric acid (H2SO4), will become ketone
carboxylic acid (IR Spectra)
- sharp peak at 1725 cm- = carbonyl (C=O) bond - broad peak between 2500 cm- & 3300 cm- = O-H bond - general formula RCOOH
Reaction of carboxylic acid & ammonia
- should produce amide - uses nucleophilic substitution - occurs via condensation reaction in which a molecule of water is removed as LG
Pi bonds
- side-to-side overlap of two p orbitals - any bond that overlaps a sigma bond - create double or triple bond
Fractional Distillation
- slows down process when BP's are < 25* apart - technique used to separate molecules based on BP
Acid Strength
- smaller pKa = more acidic - stronger acid = more stable conjugate base - resonance stabilizes conjugate-base anion - induction: electron-withdrawing groups ("EWG") 1. proximity: closer the EWG is to acidic hydrogen = stronger the acid 2. electronegativity: more electronegative EWG = stronger acid 3. quantity: larger # of EWG = stronger Acid - hybridization: more acidic w decreasing hybridization (sp > sp2 > sp3) - sp3: don't hold electrons as tight, so more willing to give them up, thus making it LESS acidic
Organic Layer of Extraction
- solubilize neutral compounds and biological and nonpolar molecules - nonpolar solvent attracts biological and neutral molecules
Aqueous layer of Extraction
- solubilize polar and ionic compounds, things that can H-bond - polar solvent attracts ions & molecules that can H-bond
Epimer
- special type of diastereomer - 2 molecules, each have 4 chiral centers - differ in configuration at only one chiral center -
Free Radical (Chain) Termination
- steps describe reactions where two free radicals combine to form one molecule - "soak up" free radicals - eventually will stop chain reaction
Nucleophiles of SN2 reaction
- strong Nu- required - Example: NaOH
Bases of E2 elimination
- strong base required - large / bulky preferred (prevents SN2) - Example: t-butoxide
nitro groups
- strongly deactivating meta directors for electrophilic aromatic substitutions - halogen will then attach to meta position
carbonyl carbon
- susceptible to nucleophilic attacks 1. it has partial positive charge bc of electron w/drawing effects of oxygen 2. it is trigonal planar = NO steric hindrance
organic extractions
- take advantage of solubility of different solutes in difficult solvents - separate solvents into organic (non-polar compounds) & aqueous (polar & charged compounds) layers - layers after extraction are due to difference in density - denser solution always at boron
Side Chain R groups
- tend to associate similarly to the concept of "like dissolves like" - groups of similar polarity will tend to group together & influence secondary & tertiary structure of protein - Examples: both groups are hydrocarbons & non-polar in nature
williamson ether synthesis
- type of SN2 reaction 1. oxygen acts as nucleophile & displaces Br 2. Br = good leaving group 3. methyl group sterically unhindered 4. methyl substrates cannot undergo Elimination (so E2 is not possible)
meso compounds
- type of diastereomer - have internal plane of symmetry - chiral centers are present, but compound is achiral
exhaustive elimination
- type of hofmann elimination - characterized by converting amine into quaternary ammonium iodide salt through excess methyl iodide (CH3-I) - treatment with silver oxide & water converts this to ammonium hydroxide - ammonium hydroxide undergoes elimination in presence of heat to form alkene & an amine - one of the products should be an alkene - first step of this hofmann elimination requires methylation of amine - final product should also encompass a tertiary amine
Polar Aprotic solvent
- unable to form H-bonds - avoids H-bonding w Nu- - molecules with NO H's directly attached to O, N, or F (so cannot H-bond) - Example: Acetone DMSO
Grignard Reagents
- use Mg, halogen, & alkyl group - Mg less electronegative than C of alkyl group - THUS, C of alkyl group becomes more electronegative & attacks C of substrate (which is usually the C of a carbonyl) - will be destroyed if it comes into contact with H-OH (water group) - will NOT react w/ carboxylic acids - WILL react with ketone & ester substrates
Gabriel Synthesis
- uses phthalimide - phthalimide restricts # of times nitrogen can react - reacts once to form N-alkylphthalimide - after work up with base, N-alkylphthalimide turns into primary amine - preferred over direct alkylation
Extraction
- uses separation funnel - less dense layer on top - more dense layer on bottom
Hydration Reaction
- water is added to molecule 1. addition of Hydrogen atom on one side 2. addition of hydroxyl group on other side
SN1 & E1
- weak base or nucleophile - protic solvent 3* > 2*
Electron withdrawing groups
-NO2
Common Trends of C NMR
0 ppm = methane 8-35 ppm = primary 15-50 ppm = secondary 20-60 ppm = tertiary 30-40 ppm = quaternary 65-85 ppm = triple bond 100-150 ppm = double bond 110-170 ppm = aromatics 190-200 ppm = carboxylic acids
Important Trends of H NMR
0-3 ppm = sp3 2-5 ppm = sp 5-7 ppm = sp2 6-8 ppm = aromatics 9-10 ppm = aldehydes 10-12 ppm = carboxylic acids *any EWG can shift values 1-2 ppm
NMR Spectrum
1. # of peaks = # of unique types of H 2. Integration = How many of each type of H 3. Chemical shift = chemical environments of each H 4. Splitting = how many neighbors for each H - concerned w/ hydrogen atoms - each peak = chemically equivalent hydrogens - splitting of peaks is caused by "neighboring hydrogens" - splitting also requires multiple peaks - THUS, can have four singlets, two triplets, long singlet - CANNOT have lone doublet - if there is only ONE signal, all protons in compound must be exactly the same
Dibromination to synthesize alkynes from alkenes
1. Alkane + Halogen (Br) goes through addition reaction 2. alkene + strong base goes through E2 elimination 3. Halogenated (Br) Alkene + strong base goes through E2 elimination 4. product = alkyne
Important Peaks of IR Spectroscopy
1. C=O: 1700-1800 cm- (sharp) 2. O-H: 3200-3600 cm- (BROAD) 3 N-H: 3200-3400 cm- (sharp)
SN2 substitution
1. Good / strong Nucleophile / weak base (ie: Cl-) CH3 > 1* > 2* 2. Good / strong Nucleophile / strong base (ie: OH-) CH3 > 1* >
IUPAC Rules
1. Identify longest C chain containing highest priority functional group 2. # C chain so highest priority functional group receives lowest # & becomes suffix 3. # remaining substituents accordingly, include them as prefixes in alphabetical order
Oxidizing agents
1. PCC 2. KMnO4 3. Sodium Dichromate
acid-catalyzed esterification
1. alcohol (ROH) acts as nucleophile 2. alcohol added to carboxylic acid 3. -OH group is protonated 4. Water molecule is displaced as LG
Esterification reaction
1. alcohol nucleophile attacks carbonyl compound 2. ester is formed
NMR Spectroscopy
1. chemical shift - chemical environment of proton - downfield (left) = closer to Electronegative elements - upfield (right) = further away from electronegative elements 2. integration - how many protons 3. splitting - # of neighboring protons - (n+1) - concerned with protons (H's)
Anti-aromatic
1. cyclic - ring 2. planar - sp2 - 120* 3. conjugated - p-orbital electrons 4. (4n) pi electrons
Aromaticity
1. cyclic - ring 2. planar - sp2 - 120* 3. delocalization - through p-orbital hybridization OR - through unshared (lone) pairs of electrons 4. Follows Huckel's Rule - (4n + 2) pi electrons - n = lone pairs - (2, 6, 10, 14, 18, etc)
E1 vs. SN1
1. first step of E1 is identical to first step of SN1 - they are the same reaction 2. second step is different! - double bond formation for E1 - substitution for SN1 3. E1 & SN1 occur simultaneously & compete 4. E1 favored by heat
Factors that stabilize the conjugate base
1. greater # of electron-withdrawing groups allows specified group's negative charge to be spread out more 2. closer the electron-withdrawing group is to the specified group
Simple Distillation
1. heat mix 2. allow substance w lower BP to boil first 3. then condense & collect distillate
Factors that Increase Solubility
1. higher temperatures 2. similar polarities - "like dissolves life" - compounds that are polar or ionic will dissolve solvents that are also polar - compounds that are non-polar will dissolve in non-polar solvents
Base Strength
1. resonance effects - help stabilize conjugate acid cation 2. induction: Electron donating groups (EDG) - greater proximity, strength, & # of EDG's = increases base strength - want to pull H+ off acid 3. Non-bonded electron pairs - non-bonded electron pairs (O or N, usually) = increase molecule's basicity 4. Hybridization - more basic / less acidic with increasing hybrization (sp3 > sp2 > sp)
Vacuum Distillation
1. separation of liquids with high BP's by reducing ambient pressure 2. lowering BP's
Substrates of E1 elimination
3* > 2* >
Substrate of SN1 reactions
3* > 2* > - more R groups help stabilize carbocation - R groups donate electron density
stability of free radicals
3° > 2° > 1° > methyl
pKa
= -logKa - inversely related to acidity - lower the value, the more acidic the substance
pKb
= -logKb - inversely related to basicity - higher the value, the less basic the substance - lower the value, the more basic the molecule - basicity increases when (for example) nitrogen is attached to alkyl groups - alkyl groups donate electrons, intensifying availability of lone pair on nitrogen
Using acids & Bases in Extraction
Acids / bases can protonate / deprotonate molecules, allowing layer switching
anti-Markovnikov Addition
Alkene + Halogen Radical --> Halogen on LESS-substituted carbon of alkane - radical = presence of UV, peroxide (ROOR / HOOH), or heat - In presence of radical, halogen goes to LEAST substituted C - Radical goes to MOST substituted C - HBr (or) HCl
Markovnikov Addition
Alkene + Hydrogen Halide --> Halogen on more substituted carbon of alkane - HBr (or) HCl - Mar substituted = Mar stable = Markovnikov - Secondary carbocation = STABLE = major product = MOST substituted - primary carbocation = NOT stable = minor product (picture: Addition of HBr to propene)
Anti Addition of Halogens
Alkene + X2 --> Halogenated alkane - Diatomic = Br2 (or) Cl2 - NO acid - Bromonium / chloronium ion intermediate - or bromonium / chloronium bridge intermediate - Bromine / Chlorine on 2 different C's - anti-conformation
Substrates of SN2 reaction
CH3 > 1* >
Formation of amide
CH3COCl + NH3 --> CH3CONH2 + HCl
reduction of acetic acid to ethanol
CH3COOH + LiAlH4/Et2O --> CH3CH2OH
Synthesis of ethanoyl chloride from acetic acid
CH3COOH + SOCl2 --> CH3COCl + SO2 + HCl
Neutralization Reaction
Example: acetic acid deprotonates in presence of strong base sodium hydroxide CH3COOH + NaOH --> CH3COO-Na+ + H2O
Hydrochloric Acid
HCl
Nitric Acid
HNO3
E1 Elimination
Heat + acid =
Stereochemistry of SN2 reaction
INVERTED - (R) -> (S) - (S) -> (R) - unless Nu- & LG are diff. priorities; if different, re-calculate
broad IR peak around 2500 cm- to 3300 cm-
N-H bond or O-H bond [IR spectra]
Nonpolar amino acid
No acidic or basic side groups
NMR
Nuclear Magnetic Resonance
Carboxylic acid
R-COOH
Kinetics of E1 elimination
Rate = k[RX]
Kinetics of SN1 reaction
Rate = k[RX] - 1st order
kinetics of E2 elimination
Rate = k[RX][Base-] - 2nd Order
Kinetics of SN2 reaction
Rate = k[RX][Nu-] 2nd order
Addition Reactions
adding groups to break double (or triple) bonds 1. Markovnikov addition 2. Anti-markovnikov addition 3. Anti Addition of Halogens
E2 Elimination
aka "Bimolecular elimination" - one step reaction - thus, has transition state - creates double bond 1. Good Nucleophile / strong base (ie: OH-) 3* > 2* 2. Bulky Nucleophile / strong base (ie: t-butoxide) 3* > 2* > 1* 3. Heat + base = ...
ethene
aka "CH2CH2 = C2H4" - both carbon atoms bonded to each other via double bond = sp2 hybridized - molecule is planar - each bond = 120° apart = minimizing electron-pair repulsion
Methanoic acid
aka "Formic acid" HCOOH
Infrared Spectroscopy
aka "IR spectroscopy" - measures molecular vibrations of characteristic *functional groups* - Used to determine chemical structure because different bonds will absorb different wavelengths of light
LiAlH4
aka "Lithium Aluminum Hydride" - reduces Carboxylic acids producing primary alcohol - reagent used to make primary alcohol from carboxylic acid - reducing agent
Sodium Dichromate
aka "Na2Cr2O7" - powerful oxidizing agent that will oxidize alcohols fully - primary alcohols will become carboxylic acids - secondary alcohols will oxidize to ketone
propanoic acid
aka "Propionic acid" CH3CH2COOH
Ultraviolet-Visible Spectroscopy
aka "UV-vis Spectroscopy" - used to exams *conjugated double bond* systems - measurement of absorptions of light between about 150 - 750 nm by substances - type of optical spectroscopy that measures absorption of light in visible & ultraviolet regions of spectrum - spectra primarily provide structural info about conjugation of multiple bonds in the compound being analyzed
Substitution: SN1
aka "Unimolecular Nucleophilic substitution" - 1 stands for 1 thing only that matters: carbocation - multiple step reaction
E1 elimination
aka "Unimolecular elimination" - creates a double bond - multiple step reaction - bases want H's - bases are H+ acceptors
acyl halide
aka "acid halide" prefix: halocarbonyl- suffix: -oyl halide
SN2 Substitution reaction
aka "bimolecular nucleophilic substitution" *think Titanic movie* - Nucleophile = Jack = lover of nucleus = negative molecule - LG = Roses' eX = halogen - Molecule / substrate = Rose - one step reaction
IR Spectroscopy
aka "infrared spectroscopy" - based on concept that certain bonds absorb E at specific frequencies - measures absorption spectrum of a molecule - tells about *functional groups* in molecule
Alkoxide substituents
aka "methoxide ion" - ortho/para directing activators of electrophilic aromatic substitutions - conjugate base of alcohol
E isomer
aka "on Epposite sides" - when two higher priority groups are on opposite sides of the double bond - when two higher priority groups are trans to each other
Z isomer
aka "on Zee Zame Zide" - when two higher priority groups are on the same side of the double bond - when two higher priority groups are cis to each other
KMnO4
aka "potassium permanganate" - reagent used to make carboxylic acid *from* primary alcohol - strong oxidizing agent - cleaves double bond by oxidation or producing geminal diol - reagent used in the conversion of a primary alcohol to a carboxylic acid in an oxidation reaction
conjugation
alternating sigma & pi bonds
Aniline
benzene with NH2
Hydroxyl (OH)
broad peak at 3300 cm-
Mechanism of E1 elimination
carbocation formation = rate determining step
Mechanism of SN1 reaction
carbocation formation is rate determining step
Mechanism of SN2 reaction
concerted / single backside attack (you don't want the new bf walking in the front door while the old boyfriend leaves the front door)
Mechanism of E2 elimination
concerted loss of H+ & LG
1-butyne
contains sp & sp3 hybridization
acetal
functional group that contains carbon atom bonded to 2 -OR groups, alkyl chain, & hydrogen atom
cis vs. trans designation
generally used only when 2 lower priority groups on each carbon atom are both hydrogen atoms
Geometric Isomers
isomers that differ in arrangement of groups about a double bond
denser layer
lay always on bottom when performing organic extraction
Hoffman Elimination
less substituted product yielded compared to Zaitsev product
anti-addition
metallic sodium in ammonia solution would cause reaction yielding trans isomer
3° > 2° > 1° > methyl
most stable form of free radical
Solvents of E1 elimination
polar protic solvent is best
Ester
prefix: alkocycarbonyl- suffix: -oate - *you get more eggs (O's) on ESTER* - *Aunt ESTER needs more O*
Ether
prefix: alkoxy- suffix: -ether - *O has C on ETHER side of it*
Amide
prefix: amino- suffix: -amide *amiDe is a Derivative*
Amine
prefix: amino- suffix: -amine structure: C-N
Carboxylic acid
prefix: carboxy- suffix: -oic acid structure: COOH ; CO2H
Nitrile
prefix: cyano- suffix: -nitrile
alkyl halide
prefix: halo- suffix: -halide X = halogen (F, Cl, Br, I)
alcohol
prefix: hydroxy- suffix: -ol structure: C-OH
Imine
prefix: imino- suffix: -imine structure: C=N *ImIne -- 2 I's make double bond*
Aldehyde
prefix: oxo- suffix: -al structure: CHO
Ketone
prefix: oxo- suffix: -one
phenyl
prefix: phenyl
Thiol
prefix: sulfhydryl- suffix: -thiol structure: C-SH - NO H-bond
chiral
reacting cyclohexene + B2 (g) Q: chiral or achiral
Substitution Reaction
reaction in which atom or group of atoms (molecule) is replaced w/ different atom or group of atoms (molecule)
Syn-Addition
reaction results in addition of 2 Hydrogen atoms on same side of molecule
HNO3 / H2SO4
reagents for nitration of aromatic compounds in electrophilic aromatic substitution reactions
H+ / H2O
reducing agent
Halogen Gases
result in anti-addition when they attack cyclic alkene
Ion-exchange chromatography
separate molecules based on their charges
thin layer chromatography
separate molecules based on their polarity
Gel Electrophoresis
separate molecules based on their size
Distillation
separation 2 liquid compounds
SN2 primary substrate
significantly lowers activation E (think SN1 or SN2)
Propagation of Free Radical
steps in which one free radical is used to generation another
alkane
suffix: -ane structure: C-C
alkene
suffix: -ene structure: C=C
alkyne
suffix: -yne
Aldol condensation reaction
two carbonyl molecules are joined with loss of water molecule
Ether Cleavage
two types: 1. straight chain 2. cyclic (ie: epoxides) - cleave of straight chain or epoxides both proceed via SN1 or SN2 - straight chain of this type are fairly stable & require strong acid (HBr or HI) & high temperature for cleavage to occur - first step of straight chain cleave = protonation of the oxygen (which facilitates either loss of LG or creates better electrophile for nucleophilic attack) - products of straight chain cleave are alcohol & alkyl halide - alcohol usually goes on to react w/ another equivalent of HBr or HI to form another alkyl halide - epoxides are strained (do NOT require harsh conditions like high temperatures or strong acids) - based-catalyzed cleavage of epoxide proceeds via SN2 (cleavage occurs on LEAST substituted carbon)
