Organic Chemistry

Lewis acid and Lewis base

- Lewis acid - electron receptor, electrophiles, vacant p-orbitals into which they can accept an electron pair, or are positively polarized atoms - Lewis base - electron donor, nucleophiles, lone pair of electrons that can be donated, are often anions, carrying negative charge

Carboxylic acid reduction

- to primary alcohol using LiAlH4 - NaBH4 is not strong enough = no reaction

Cyanohydrins

Hydrogen cyanide reacts with carbonyls to form cyanohydrins, a stable product

Which reactant could be combined with butanol to form butyl acetate?

(CH3CO)2O and catalytic acid - In order to prepare butyl acetate from butanol, we need to perform a nucleophilic acyl substitution reaction - If the product is an ester, we need to start with a reactant that is more reactive than ester, or the reaction will not proceed. - Anhydrides are more reactive than esters

Between a monocarboxylic acid, a dicarboxylic acid, and a dicarboxylic acid that has been deprotonated once, which will be the most acidic?

- A dicarboxylic acid would be the most acidic, as the second carboxyl group is electron-withdrawing and therefore contributes to even higher stability of the anion after loss of first hydrogen - Monocarboylic acid is more acidic than a deprotonated dicarboxylic acid because carboxylate anion is electron-donating and destabilizes the product of the second protonation step, deceasing acidity

Mesylates and tosylates

- Alcohols can be converted to mesylates or tosylates to make them better leaving groups for nucleophilic substitution reactions (protecting groups) - Mesylates - contain functional group -SO3CH3, derived from methanesulfonic acid - Tosylates - contain functional group -SO3C6H4CH3, derived from toluenesulfonic acid - Removed using strong acid

Acetal and ketal

- Aldehydes and ketones can be protected by converting them into acetals or ketals using diol - Acetal and ketal can be converted back to a carbonyl by catalytic acid (deprotection) using aqueous acid

keto-enol tautomerization

- Aldehydes and ketones list in the traditional ketones form (C=O) and as the less common enology tautomer (enol = ene + ol) - Deprotonated enolate can act as nucleophile - Not resonate structures due to different connectivity of atoms

Nucleophilic acyl substitution reactions

- All carboxylic acid derivatives can undergo nucleophilic substitution reactions - The rate at which they do so are determined by their relative reactivities - Anhydrides can be cleaved by addition of nucleophile + addition of ammonia or amine results in amide and carboxylic acid + addition of alcohol results in ester and carboxylic acid + addition of water results in two carboxylic acids

Phenols

- Benzene rings with hydroxyl groups - Named for relative positions of hydroxyl groups + ortho (o) = adjacent carbons + meta (m) = separated by one carbon + para (p) = opposite side of ring

Bonding vs. antibonding orbitals

- Bonding orbitals are more stable than anti bonding orbitals; therefore anti bonding orbitals have higher energy

Bronsted-Lowry acid and base

- Bronsted-Lowry acid - proton donator - Bronsted-Lowry base - proton acceptor water can act as either acid or base - amphoteric

Reducing agents

- Donate electrons, get oxidized - have low electronegativity and ionization energy - contain a metal or large number of hydrides - aldehydes, ketones, and carboxylic acids can be reduced to alcohols by lithium aluminum hydride (LiAlH4) - Amides can be reduced to amines by LiAlH4 - Esters can be reduced to alcohols by LiAlH4

Configurational isomers

- Enantiomers - nonsuperimposable mirror images and thus have opposite stereochemistry at every chiral carbon; same chemical and physical properties except for rotation of plane-polarized and reactions in a chiral environment - Optical activity - ability of molecule to route plane-polarized light: d- or (+) molecules rotate light to the right; l- or (-) molecules rotate light to the left + Specific rotation = observed rotation/(cxl) c = concentration in g/ml, l = path length in dm - Racemic mixtures - equal concentrations of two enantiomers, not optically active because the two enantiomers' rotations cancel each other out - Meso compounds - has chiral center but contains internal plan of symmetry, optically inactive because two sides of molecule cancel each other out

Peptide bond formation and cleavage

- Formed by condensation reactions - Resonance of peptide bond restricts motion about the C-N bond, which takes on partial double bond character due to resonance + some sp2 character - planar - Strong acid or base needed to cleave peptide bond

High-performance chromatography

- Historically, HPLC was performed at high pressures whereas column chromatography uses gravity to pull solution through column - Now, HPLC is performed with sophisticated and variable solvent and temperature gradients, allowing for much more specific separation of compounds + high pressures is no longer required - It is used if the sample size is small or if forces such as capillary action will affect the results - Formerly called high-pressure liquid chromatography

Hemiacetals and - Acetals and ketals

- In the formation of hemiacetals and hemiketals - alcohol is the nucleophile and the carbonyl carbon is the electrophile + these molecules are short-lived and unstable - In the formation of acetals and ketals (SN1) - alcohol is the nucleophile, and the carbocation carbon (formerly carbonyl carbon) is the electrophile + Hydroxyl group is protonated under acidic conditions and lost as water

Kinetic and thermodynamic enolats

- Kinetic- favored by fast, irreversible reactions at lower temp with strong, sterically hindered bases + double bond to less substituted α-carbon upon removal of α-hydrogen because less steric hindrance - Thermodynamic - favored by slower, reversible reactions at higher temp with weaker, smaller bases + double bond to more substituted α-carbon

pKa values for common functional groups

- Left: +; right: - - acids: alcohols, aldehydes, ketones, carboxylic acids, most carboxylic acid derivatives - bases: amines, amides

Induction

- uneven distribution of charge across sigma bond because of differences in electronegativity - More electronegative groups = greater reactivity

Nuclear magnetic resonance (NMR) spectroscopy

- Measures alignment of nuclear spin with an applied magnetic field, which depends on the magnetic environment of the nucleus itself - Useful for determine structure (connectivity) of a compound, including functional groups + nuclei may be in the lower-energy α-state or higher energy β-state + radiofrequency pulses push the nucleus from α to β-state, and these frequencies can be measured - Magnetic resonance imaging is a medical application - NMR are generally plotted as frequency vs. absorption of energy. They are standardized by using chemical shift, measured in ppm + NMR spectra are calibrated using tetramethylsilane (TMS) with chemical shift of 0 ppm + higher chemical shifts are located to the left (downfield) - Proton (1H) NMR is the most common + each unique group of protons has its own peak + integration (area under the curve) of this peak is proportional to the number of protons contained under the peak + Deshielding of protons occurs when electron-withdrawing groups pull electron density away from nucleus, allowing it to be more easily affected by magnetic field - moves peak further downfield + When hydrogens are on adjacent atoms, they interfere with each other's magnetic movements, causing spin-spin coupling (splitting) + A proton's peak is split into n+1 sub peaks, where n is the number of protons that are three bonds away from the proton of interest + splitting pattern include doublets, triplets, and multiplets + Protons on sp3-hybridized carbons: 0-3ppm (but higher if electron-withdrawing groups are present) + Protons on sp2-hybridized carbons: 4.6-6 ppm + Protons on sp-hybridized carbons: 2-3 ppm + Aldehyde: 9-10 ppm + Carboxylic acid: 10.5-12 ppm + Aromatic hydrogens: 6-8.5ppm *Nuclei with odd mass numbers (1H, 11B, 13C) or those with even mass number but off atomic number (2H, 10B) will have nonzero magnetic moment - show up + 12C does not show up - zero magnetic moment

Imines and Enamines (tautomerization)

- Nitrogen and nitrogen derivatives react with carbonyls to form imines, oxides, hydrazones, and semicarbazones (condensation because H2O is lost) - Imines can tautomerize to form enamines

Nucleophilic acyl substitution

- Nucleophile attacks, opening carbonyl and forming tetrahedral intermediate - carbonyl then reforms, kicking off the leaving group - favored by acidic or basic conditions

Bimolecular nucleophilic substitution (Sn2) reactions

- One step (no intermediate) + Nucleophile attacks at the same time as LG leaves - Must perform backside attack, leading to inversion of stereochemistry - Absolute configuration is changed from R to S or vice versa if nucleophile and LG have the same priority - Prefer less-substituted carbons because alkyl group create steric hindrance and inhibit nucleophile from accessing the electrophilic substate carbon - Rate dependent on both substrate and nucleophile: rate = k[Nu:][K-L]

Phosphorus-containing compounds

- Phosphorus is found in inorganic phosphate (Pi), a buffered mixture of HPO42- and H2PO4- (the two that have highest concentrations at physiological pH) - Phosphorus is found in the backbone of DNA, which uses phosphodiester bonds + in forming these bonds, a pyrophosphate (PPi, P2O74-) is released; + in aqueous solution - pyrophosphate is hydrolyzed to two Pi - Phosphate groups are high energy because of large negative charges in adjacent phosphate groups and resonance stabilization of phosphates - Organic phosphates - carbon-containing compounds that also have phosphate groups (ATP, GTP, DNA) - Phosphoric acid - an excellent buffer because it has 3 hydrogens with Pka that span nearly the entire pH scale

Polar protic and polar aprotic solvents

- Polar protic solvents - capable of H bonding + nucleophilicity increases down the periodic table: I- > Br- > Cl- > F- - Protons in this solution will be attracted to the nucleophile - Polar aprotic solvents - incapable of H bonding + nucleophilicity increases up the periodic table similar to basicity: F- > Cl- > Br- > I- - Always assume it is in a polar solvent. - Both aprotic and protic can dissolve nucleophiles and assist in electron moving. *cannot use nonpolar solvents in nucleophile-electrophile reactions because reactants are polar - they wouldn't dissolve

Quinones and hydroxyquinones

- Quinones - synthesized through oxidation of phenols + Resonance-stabilized electrophiles + Vitamin K1 (phylloquinone) and vitamin K2 (menaquinone) are examples of biochemically relevant quinones - Hydroxyquinones - produced by oxidation of quinones, adding a variable number of hydroxyl groups - Ubiquinone (coenzyme Q) - biologically active quinone that acts as an electron acceptor in complexes I, II, III of ETC; reduced to ubiquinol + conjugated rings, which stabilize molecule when accepting electrons + long alkyl chain allows for lipid solubility, allowing molecule to function in phospholipid bilayer - From phenol to hydoxyquinone = 2 oxidation steps

Carbonyl (C=O)

- Reactivity dictated by polarity of the double bond; carbon has a partial positive charge is electrophilic - Electron withdrawing (because oxygen is electronegative) - Resonance structure of functional group places a positive charge on the carbonyl carbon (electrons go to oxygen) - Carbonyl-containing compounds have higher boiling points than equivalent alkanes because of dipole interactions - Alcohol have higher boiling points than carbonyls because of hydrogen bonding

Resonance structure

- Resonance structures can be favored because they lack formal charges or form full octets on highly electronegative atoms, like oxygen and nitrogen - Stabilization of positive and negative charges through induction and aromaticity can also favor certain resonance structures

Saponification

- Soap - long chain carboxylic acids (fatty acids) with strong base - Contains hydrophilic carboxylate head and hydrophobic alkyl chain tail - Soaps organize in hydrophilic environments to form micelles which dissolve non polar organic molecules in its interior and can be solvated with water due to its exterior shell of hydrophilic groups

Fischer projection

- Switching a pair of substituents - enantiomers - Switching two pairs of substituents - same - Rotating molecule by 90 - enantiomers - Rotating molecule by 180 - same

Aldol condensation

- The carbonyl-containing compound acts as both a nucleophile and an electrophile - Enolate carbanion acts as nucleophile (deprotonated aldehyde or ketone) + Step 1: forming the aldol + Step 2: dehydration of the aldol (need base and high temp, occur by E1 or E2) - Can be halted with addition of acid - aldol = aldehyde and alcohol - Condensation. dehydration, nucleophile-electrophile

Chemoselectivity

- The more oxidized the functional group, the more reactive it is in both nucleophile-electrophile and oxidation-reduction reactions - one can make use of steric hindrance properties to selectively target functional groups that night not primarily react or to protect functional groups + diols are often used as protecting groups for aldehyde and ketone carbonyls. + alcohols may be protected any conversion to tert-butyl ethers

Steric hindrance

- when reaction cannot proceed (or significantly slows) because of substituents crowding the reactive site. - Protecting groups (e.g. acetals) can be used to increase steric hindrance or otherwise decrease reactivity of a particular portion of molecule - if we want to push a reaction in SN1 direction rather than SN2, use a tertiary substrate

Unimolecular nucleophilic substitution (SN1) reactions

- Two steps (with intermediate) + LG leaves, forming carbocation (rate-limiting) + Nucleophile attacks planar carbocation from either side, leading to a racemic mixture of products - prefer more substituted carbons because alkyl groups can donate electron density and stabilize positive charge of carbocation - anything that accelerates formation of carbocation accelerate SN1 reactions - Rate is dependent on substrate (1st order): rate = k[R-L] *R-L is alkyl group with leaving group

Jones oxidation

- Use CrO3 - Need acidic conditions, aqueous conditions (not anhydrous which means no water) - Heat speeds up reaction but is not required

Chromatography

- Uses two phases to separate compounds based on physical and chemical properties - Stationary phase or absorbent is usually a polar solid - Mobile phase runs through stationary phase and is usually a liquid or gas. This elutes the sample through the stationary phase - Compounds with higher affinity for stationary phase have smaller retardations factors and take longer to pass through, if at all - Compounds with higher affinity for mobile phase elute through more quickly - Compounds therefore get separated from each other (partitioning)

Nucleophilic addition reactions

- When a nucleophilic attacks and forms a bond with carbonyl carbon, electrons in π bond are pushed to oxygen atom - No good leaving group (aldehydes or ketones) - carbonyl remains open; protonated to form an alcohol - Good leaving group (carboxylic acids and derivatives) - carbonyl reforms; kick off leaving group

E and Z designation for alkenes

- Z - two highest-priority groups on same side - E - two highest-priority groups on opposite sides Also cis-trans isomers, a form of diastereomers

Oxidizing agents

- accept electrons, get reduced - high oxidation state, high affinity for electrons - often contain a metal or large number of oxygens - Primary alcohols can be oxidized to aldehydes by pyridinium chlorochromate (PCC) or to carboxylic acids by chromium troxide (CrO3) or sodium or potassium dichromate (Na2Cr2O7 or K2Cr2O7) - Secondary alcohols can be oxidized to ketones by most oxidizing agents - Aldehydes can be oxidized to carboxylic acids by most oxidizing agents

Properties of alcohols

- alcohols can hydrogen bonds, raising their boiling points and melting points relative to corresponding alkanes - Hydrogen bonding also increases solubility of alcohols - Phenols are more acidic than other alcohols (smallest pka, highest ka) because the aromatic ring can delocalize the charge of the conjugate base - Electron-donating groups (alkyl groups) decrease acidity because they destabilize negative charges. + activate the ring toward reactions + tend to be in ortho and para positions - Electron-withdrawing groups (electronegative atoms and aromatic rings) increase acidity because they stabilize negative charges + deactivate the ring toward reactions + tend to be in meta positions

Aldehyde and ketone

- aldehyde (C1): suffix -al - ketone (C2): suffix -one - common names + methanal = formaldehyde + ethanal = acetaldehyde + propanal = propionaldehyde + propanone = acetone

Amino acids

- alpha carbon attached to an amino group, a carboxyl group, a hydrogen atom, and an R group - It is a chiral center in all amino acids except glycine because R group is H - All naturally occurring amino acids in eukaryotes, except glycine are optically active, and all are L-isomers (amino group on the left) - All L-amino acids have (S) configuration, except for cysteine - amphoteric - act as both acid and base (acidic characteristics from carboxylic acids and basic characteristics from amino groups) + In neutral solution, amino acids exist as twitterions - Can be classified by R groups + nonpolar nonaromantic - GAVLIMP + aromatic - T, F, W (hydrophobic, interior of protein) + polar - S, T, N, Q, S + negatively charged - D, E + positively charged - R, K, H

Carboxylic acids

- always terminal - methanoic acid = formic acid - ethanoic acid = acetic acid - propanoic acid = proprionic acid

Hydrolysis of amides

- amides can be hydrolyzed to carboxylic acids under strongly acidic or basic conditions + strongly acidic conditions - protonate oxygen in the carbonyl to increase the electrophilicity of the carbon, making it more susceptible to nucleophilic attack + strongly basic conditions - increase concentration of OH-, which can act as nucleophile on amide carbonyls - the attacking nucleophile Is water or hydroxide anion

Dicarboxylic acids

- carboxylic acid group on each end of molecule - Hydroxyl hydrogen and a-hydrogen (less) are acidic

Diols

- contain two hydroxyl groups - geminal diol - hydroxyl groups on the same carbon - vicinal diol - hydroxyl groups on adjacent carbons

Electrophiles (Lewis acid)

- electron loving - contain positive charge or (+) polarized - more positive compounds are more electrophilic - alcohols, aldehydes, ketones, carboxylic acids, and their derivatives can act as electrophiles

Esterification

- formation of an ester from a carboxylic acid and an alcohol, with the elimination of a molecule of water in the presence of an acid catalyst - occur in the presence of an acid catalyst and heat - should not be carried out in water because water molecule would hydrolyze the desired products back to the parent carboxylic acid

Strecker synthesis

- generates an amino acid from an aldehyde - a condensation reaction (formation of mine from carbonyl containing compound and ammonia, with loss of water), followed by nucleophilic addition (addition of nitrile group), followed by hydrolysis - planar intermediates, can be attacked from either side, forming a racemic mixture of enantiomers - optically inactive

Gabriel synthesis

- generates an amino acid from potassium phthalimide, diethyl bromomalonate, and an alkyl halide - water is then used to hydrolyze the resulting compound to form the amino acid - while acids and bases are used at various times as catalysts, they are not main reactants - proceeds through two SN2 reactions, hydrolysis, and decarboxylation - planar intermediates, can be attacked from either side, forming a racemic mixture of enantiomers - optically inactive

π bond vs. σ bond

- σ bond - head-to-head overlap of two s-orbital or hybridized orbitals, electron density concentrated between two nuclei - π bond - parallel overlap of unhybridized p-orbitals, electron density contracted above and below the bonding axis

α-hydrogens

- hydrogens attached to the α- carbons (in aldehydes and ketones) - acidic due to both inductive and resonance effects + α-hydrogens in aldehydes are slightly more acidic due to the electron-donating characteristics of the second alkyl group in ketones. This extra alkyl group destabilizes the carbanion, disfavoring the loss of α-hydrogens - can be removed with strong base - electron withdrawing oxygen of carbonyl weakens the C-H bonds on α-carbons - Enolate resulting from deprotonation can be stabilized by resonance with carbonyl *Electron withdrawing groups like oxygen stable organic anions *Electron donating groups like alkyl groups destabilize organic anions - α-hydrogens of aldehydes and ketones are acidic due to both inductive and resonance effects

Strain

- increased strain in a molecule can make it more reactive - β-lactams are prone to hydrolysis because of significant ring strain - ring strain = torsional strain from eclipsing interactions - angle strain = compressing bond angles below 109.5 degrees

Tautomers

- isomers that can be interconverted by moving a hydrogen and a double bond - keto and enol form

IUPAC name

- longest parent chain possible - alphabetical order - highest priority uses suffix

Acid dissociation constant, Ka

- measure acidity - HA dissociates inton H+ and A- - Equation: Ka = [A-][H+]/[HA] - Equation: pKa = -log Ka - lower pKa = stronger acid - pKa decreases down the periodic table and increases with electronegativity

Ultraviolet (UV) Spectroscopy

- measures absorption of UV light, which causes movement of electrons between molecular orbitals - Most useful for studying compounds with double bonds and/or heteroatom with lone pairs that create conjugated system - UV spectra are generally plotted as % transmittance or absorbance vs. wavelength - Two appear on UV spectrum, a molecule must have a small enough energy difference between its highest occupied molecular orbital (HOMO) and its lowest unoccupied molecular orbital (LUMO) to permit an electron to move from one orbital to the other + the smaller the difference between HOMO and LUMO, the longer the wavelengths a molecule can absorb + conjugation occurs in molecules with unhybridized p-orbitals + conjugation shifts the absorption spectrum to higher maximum wavelengths (lower frequencies)

Infrared (IR) spectroscopy

- measures absorption of infrared light, which causes molecular vibration (stretching, bending, twisting, and folding) - useful for distinguishing functional groups or double vs. triple bonds - IR spectra are generally plotted as percent transmittance and wavenumber (1/λ) + the normal range of spectrum is 4000 to 400 cm-1 + fingerprint region is between 1500 and 400 cm-1 (contains peaks used to identify compound) - To appear on an IR spectrum, vibration of a bond must change the bond dipole moment + O-H - broad, 3300cm-1 (alcohols, water) + O-H in carboxylic acid - 3000 cm-1 + N-H - sharp, 3300cm-1 (amines, amines, amides) + C=O - sharp, 1750 cm-1 (aldehydes, ketones, carboxylic acids, amides, esters, anhydrides) - higher order bonds (double, triple, conjugated) tend to have higher absorption frequencies - band occurs at lower wavenumber - Two enantiomers will have identical IR spectra because same functional groups

Leaving groups

- molecular fragments that retain e- after heterolysis - Weak bases (conjugate of strong acids such as I-, Br-, Cl-) are more stable w/ extra electrons = good leaving groups - Alkanes and hydrogen ions are almost never LG because they form reactive, strongly basic anions

Nucleophiles (Lewis base)

- nucleus loving - contain lone pairs or π bonds - increased electron density and often (=) - nucleophilicity - similar to basicity but nucleophilicity is a kinetic property while basicity is thermodynamic - amino groups are common - CHON with (-) or lone pair - more basic nucleophile, more reactive it is (true for the same row) - more negative = better nucleophile - more electronegative = worse nucleophile - protic solvent decreases reactivity of nucleophile because it can protonate or hydrogen bond with nuc

Carboxylic acids

- polar - can form hydrogen bond - tend to form dimers - acidity due to resonance stabilization and stability of carboxylate anion which is resonance stabilized by delocalization with two electronegative oxygen atoms - electron-withdrawing substituents make anion more stable and increase acidity + CH3CCl2COOH is more acidic than CH3CHClCOOH - electron-donating substituents destabilize the anion and decrease acidity - The closer the substituent is to carboxylic acid, the stronger the effect - Strong acid, weak conjugate base, proton ready to leave - Hydroxyl hydrogen is the most acidic proton - Higher boiling point than alcohol because stronger hydrogen bond

Conjugation

- presence of alternating single and multiple bonds, which creates delocalized pi electron clouds above and below the plane of molecule - electrons experience resonance through the unhybridized p-orbitals, increasing stability - conjugated carbonyl-containing compounds are more reactive because they can stabilize their transition state (multiple resonance structures) - conjugation and resonance are more powerful than induction

Retro-aldol reaction

- reverse of aldol condensation reaction - favored by the addition of base and heat - a bond between a and B carbons of a carbonyl is broken - form an aldehyde and a ketone

Hybridization

- s character of sp, sp2, sp3 + sp: 50% s , 50% p + sp2: 33% s, 67% p + sp3: 25% s, 75% p

Distillation

- separates liquids according to differences in boiling points - liquid with lowest boiling point vaporizes first and is collected as the distillate - Simple distillation - bp < 150 and at least 25 apart - Vacuum distillation - bp > 150 to prevent degradation of product - Fractional distillation - bp less than 25 apart because it allows more refined separation of liquids by bp

Diastereomers

- stereoisomers that are not mirror images - different physical and chemical properties

Oxidation state

- the charge an atom would have if all its bonds were completely ionic - CH4 is the lowest oxidation state of carbon (most reduced) - CO2 is the highest oxidation state of carbon (most oxidized) - Carboxylic acids and derivatives are the most oxidized functional groups, followed by aldehydes, ketones, imines, followed by alcohols, alkyl halides, m and amines

Recrystallization

- the product is dissolved in a minimum amount of hot solvent - if the impurities are more soluble, the crystals will reform while the flask cools, excluding the impurities

sterioisomers

2^n n = number of chiral carbons

Common names of alcohols

2-propanol = isopropyl alcohol ethanol = ethyl alcohol

Transesterification

= exchange of one esterifying group for another on an ester - the attacking nucleophile is an alcohol

Aldehydes and ketones

Aldehydes - terminal functional groups containing a carbonyl bound to at least one hydrogen - use the suffix -al and the prefix oxo- - in rings indicated by suffix -carbaldehyde - commonly produced by oxidation of primary alcohols using week oxidizing agents like PCC - Can be oxidized to carboxylic acid with strong agents (not PCC) such as KMnO4, CrO3, Ag2O, H2O2 - Can be reduced to primary alcohols by hydride agents such as LiAlH4, NaBH4 Ketones - internal functional groups containing carbonyl boned to two alkyl chains - use suffix -one, prefix oxo- or keto- - commonly produced by oxidation of secondary alcohols using either weak or strong oxidizing agents - Cannot be further oxidized - Can be reduced to secondary alcohols using hydride agents such as LiAlH4, NaBH4

Alkane

C(n)H(2n+2)

Order of priority of functional groups

Carboxylic acid > anhydride > ester > amide > aldehyde > ketone > alcohol > alkene or alkyne > alkane

What would be formed if methyl bromide were reacted with phthalimide and followed by hydrolysis with an aqueous base?

CH3Nh2

Extraction

Combines two immiscible liquids, one of which easily dissolves the compound of interest - Depends on like dissolves like - Aqueous phase - polar (water) layer, dissolves compounds with hydrogen bonding or polarity - Organic phase - non polar layer, dissolve nonpolar compounds - Most to least likely to move to aqueous layer Hydrogen bonding > Dipole-dipole > Van der Waals - Extraction is carried out in a separators funnel - one phase is collected, the solvent is evaporated + more common for organic layer to be on top because less dense - Acid-base properties can be used to increase solubility HA + base -> A- + H-base+ *acid dissolves better in aqueous base +When acid dissociates, anion formed will be more soluble in aqueous layer than original protonated acid because it's charged. Thus adding a base will help to extract acid into aqueous phase - It's better to do multiple sequential extractions than one large one

Anhydrides

Condensation dimers of carboxylic acids - suffix -anhydride - Symmetric anhydrides are named for the parent carboxylic acid, followed by anhydride - Asymmetric anhydrides are named by listening the parent carboxylic acids alphabetically, followed by anhydride - Some cyclic anhydrides can be synthesized by heating dioic (dicarboxylic) acids - Five or six membered rings are generally stable

Amides

Condensation products of carboxylic acids and ammonia or amines - suffix -amide - alkyl group on a substituted amide are written at the beginning of the name with prefix N- - lactams = cyclic amides, named by Greek letter of the carbon forming the bond with oxygen + β-lactam, γ-lactam - Inactive, need strong acid or base for nucleophilic acyl substitution reaction

Esters

Condensation products of carboxylic acids with alcohols (Fischer esterification) + fastest when least steric hindrance - suffix -oate - Esterifying group is written as a substituent, without a number - Lactones = cyclic esters; names by number of carbons in the ring and Greek letter of the carbon forming the bond with oxygen + α-acetolactone, β-propriolsctone - Triacylglycerols - 3 esters bonds between glycerol and fatty acids

Steric hindrance

Ketones are slightly less likely to react with nucleophiles than aldehydes because the extra alkyl group destabilizes the carbanion and increases steric hindrance

physical vs chemical properties

Physical - melting & boiling point, solubility, odor, color and density Chemical - reactivity of molecules resulting in change in composition, usually dictated by reactivity of various functional groups

Cyclic conformations

Ring strain - angle strain - stretching or compressing angles from normal size - torsional strain - eclipsing formations - nonbonded strain (van Der Waals s repulsion) - interactions between substituents attached to nonadjacent carbons Cyclic molecules adopt nonplanar shapes to minimize this strain

Gas chromatography

Separates vaporizable compounds according to how well they adhere to the absorbent in the column - Stationary phase - coil of crushed metal or polymer - Mobile phase - nonreactive gas - The sample is injected into the column and moves with the gaseous mobile phase through a stationary liquid or solid phase; a computer identifies the sample components - May be combined with mass spectrometry, which ionizes fragments molecules and passes these fragments through a magnetic field to determine molecular weight or structure

Thin-layer and paper chromatography

Used to identify a sample - Stationary phase - polar material (silica, alumina, paper) - Mobile phase - nonpolar solvent, which climbs the card through capillary action - The card is spotted and developed Rf values = distance spot moved / distance solvent front moved - Reverse-phase chromatography - uses nonpolar card with polar solvent

Column chromatography

Uses polarity, size, or affinity to separate compounds based on their physical or chemical properties - Stationary phase - column containing silica or alumina beads - Mobile phase - nonpolar solvent - travels through column by gravity - Ion-exchange chromatography - beads are coated with charged substances to bind compounds with opposite charge - Size-exclusion chromatography - beads have small pores which trap smaller compounds and allow larger compounds to travel through faster - Affinity chromatography - column is made to have high affinity for a compound by coating the beads with a receptor or antibody to the compound

Nucleophilic acyl substitution - amides, anhydride, esters

amide = carboxylic acid + amine or ammonia (NH3) + cyclic = lactam ester = carboxylic acid + alcohol + cyclic = lactone anhydride = carboxylic + carboxylic + cyclic = anhydride

Michael addition

an enolate attacks an α,β-unsaturated carbonyl, creating a bond

Nucleophilic substitution ranking

anhydride > ester > carboxylic acid > amide

Filtration

isolates a solid (residue) from a liquid (filtrate) - Gravity filtration - used when product of interest is in the filtrate + Hot solvent is used to maintain solubility - Vacuum filtration - used when the product of interest is the solid + vacuum is connected to the flask to pull solvent through more quickly

Decarboxylation of carboxylic acids

loss of CO2 when heated COR and COOH not dicarboxylic acid

Substitution reactions

process when nucleophile is a stronger base (more reactive) than the LG

Wash

reverse of extraction, in which a small amount of solute that dissolves impurities is run over the compound of interest

Rank orbitals in decreasing order of strength

triple bond > double bond > σ bond > π bond

Hydration

water adds to carbonyl, forming a geminal diol