Organic Chemistry Lab Final

Front 1

Extraction

Back 1

separates dissolved substances based on differential solubility in acqueous vs. organic solvents.

Front 2

Filtration

Back 2

simple physical separation of solid and liquid phases. Mixture is poured into a funnel where it passes through a porous material which retains the solid phase, allowing the liquid phase to pass through

Front 3

Gravity filtration

Back 3

used when the liquid phase contains the material of interest and the solid is the undesired material

Front 4

vacumm filtration

Back 4

used when the material of interest is the solid and the liquid is the undesired. Usually used during a recrystallization sequence to recover the desired compound after it is cooled and crystallized.

Front 5

Distillation

Back 5

separates liquids based on boiling point, which in turn depends on intermolecular forces.

Front 6

Simple distillation

Back 6

can separate two mutually soluble substances which differ in boiling points by 80 degrees Celsius or more.

Front 7

Fractional distillation

Back 7

separates components of liquid mixtures in which the boiling points differ as little as 25 degrees celsius.

Front 8

Recrystallization

Back 8

organic solids are purified. As crystals grow, the molecules assemble in a tightly packed repeating lattice structure which usually accomodates no impurities. As crystalline forms from a solution, impurities will be exclused from the crystals.

Front 9

Chromatography

Back 9

uses a stationary phase and mobile phase to separate compounds based on how tightly they adhere based on polarity and size of compound.

Front 10

Gas chromatography

Back 10

used to separate volatile organic compounds. May be applied to identify the compounds within an unknown mixture or to determine relative amounts of compounds.

Front 11

Thin layer chromatography

Back 11

used to determine the purity of a compound, the status of an ongoing reaction or as a preliminary means of identification.

Front 12

Stationary phase

Back 12

SiO2 or Al2O3 is a polar solid to which the components of a mixture may adsorb with different affinities depending on their polarities.

Front 13

Mobile phase

Back 13

nonpolar organic solvent that travels through the stationary phase and carries components of the mixture along at different rates because of their different affiinities for the stationary phase and results in separation.

Front 14

Column chromatography

Back 14

mobile phase of organic solvent which passes through a column of finely powdered solid material. The mobile phase carries the components of the mixture through the column at different rates, separating them.

Front 15

Infrared Spectroscopy

Back 15

functional groups absorb IR radiation at specific frequencies according to the types of bonds they contain and the different vibrations they can exhibit, for example, stretching or bending of the bond.

Front 16

NMR

Back 16

provides a spectrum of peaks containing information on the numer of spin-active nuclei in a compound, most often protons and carbons. Indicates how structural features are connected.

Front 17

Terpenes

Back 17

general class of compounds which are composed from unites of isopene. These compounds have carbon counts which are generally multiples of five.

Front 18

Supercritical fluid

Back 18

form of matter which is neither liquid nor gas, but has properties of both.

Front 19

Supercritical CO2

Back 19

organic solvent that is excellent for extracting essential oils. Non-flammable, readily available, relatively non-toxic and easy to remove from the product.

Front 20

Aromatic heterocycles

Back 20

cyclic compounds which meet all the criteria for aromaticity, but contain one or more non-carbon atoms in the ring.

Front 21

Benzene and aromatic heterocycles undergo ......?

Back 21

electrophilic aromatic substitution reactions

Front 22

Porphyrin

Back 22

complex heterocyclic compound composed of four pyrrole units, each of which is linked together by carbon-carbon bonds to form a large ring with four nitrogens pointing inward forming a cavity that can accomodate metal ions.

Front 23

heme

Back 23

contains iron

Front 24

vitamin b12

Back 24

cobalt containing

Front 25

Chlorophyll

Back 25

binds magnesium

Front 26

How would you synthesize a porphyrin-containing compound?

Back 26

Electrophillic aromatic substitution

Front 27

tetraphenylporphryin

Back 27

compound used to make photoelectrodes for harvesting solar energy. Made in lab from benzaldehyde and pyrolle.

Front 28

Purpose of Uv spectrum

Back 28

used to calculate the concentration of product and can confirm both the identity and purity of the product.

Front 29

Eribulin/Halaven

Back 29

chemotherapy drug, most complex clinically approved drug to be produced by synthesis.

Front 30

1st step in synthesis of adipic acid

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dehydration of cyclohexanol

Front 31

Dehydration of cyclohexanol is a ....... reaction

Back 31

E1 mechanism

Front 32

1,2-glycol formation

Back 32

reaction which adds two hydroxyl groups at the two carbons previously involved in the alkene pi bond. Accomplished by cold KMn04 or catalytic amount of Os04. Hot KMn04 further cleaves the C-C bond of the 1,2-glycol and produces two aldehydes or ketones. Further oxidized to carboxylic acids under these same conditions.

Front 33

2nd step of adipic acid synethsis

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oxidative cleavage of cyclohexene to adipic acid.

Front 34

Adipic acid

Back 34

nylon is composed to repeating units of adipic acid.

Front 35

Oxidative cleavage of alkenes is made catalytic to avoid oxide waste by

Back 35

combination of sodium tungstate with hydrogen peroxide

Front 36

Phase transfer catalysis

Back 36

tetraalkylammonium ion such as Aliquat 336 is soluble in both water and organic phase and transfers a tungstate ion from aqueous phase into the organic phase where it can react with the alkene.

Front 37

Wittig reaction

Back 37

method of forming carbon carbon double bonds by converting aldehydes and ketones into alkenes.

Front 38

ylide

Back 38

neutral compound porduced from phosphonium salt being depronated by a strong base.

Front 39

triphenylphosphine oxide

Back 39

contains a strong P=O bond and is produced as a side product in the Wittig reaction

Front 40

What precipitate will form under the conditions in the Wittig lab?

Back 40

trans-4,4-bpe

Front 41

Cycloadditions reactions are powerful because?

Back 41

prepare at least two bonds and up to four stereogenic centers in a single step.

Front 42

Diels-Alder

Back 42

produces cyclohexene derivatives through a [4+2] cycloaddition between butadienes and alkenes.

Front 43

[2+2] cycloaddition reactions

Back 43

two alkenes react to make a four-membered cyclobutane ring.

Front 44

Resorcinol

Back 44

template that holds the alkenes in close proximity so that they can react efficiently and selectively

Front 45

[2+2] cycloaddition of trans-1,2-bis(4-pyridyl)ethene is carried out in .....

Back 45

the solid state

Front 46

[2+2] cycloaddition can't occur without

Back 46

LIGHT. UV light is used in lab to induce cycloaddition

Front 47

Why is sunlight damaging to DNA?

Back 47

neighboring thymines in DNA are stacked close to each other in space and are dimerized through photocycloaddition when exposed to light. Destructive to DNA becauses causes errors in the genetic code and causes skin cells to die=sunburn. Some cases disrupted genetic code leads to skin cancer cells.

Front 48

Number of possible steroisomeric products in Diels-Alder

Back 48

limited by the mechanism, which is stereospecific and selective for endo products

Front 49

[2+2] photocycloaddition in liquid state produces..

Back 49

eight stereoisomeric products

Front 50

Template works by using

Back 50

position two reactant molecules in close proximity and well-defined orientations, using noncovalent forces in the form of hydrogen bonds.

Front 51

What are teh two rules that describe how C=C bonds should be arranged in the solid state to undergo a [2+2] cycloaddition?

Back 51

the C=C bonds must adopt a parallel orientation, the C=C bonsd must be within 4.2 A of each other.

Front 52

Resorcinal bonding

Back 52

possess two polarized O-H bonds, located at the 1 and 3 positions of the benzene ring. Separation distance of two oxygen bonds is 4.7 A.

Front 53

co-crystallization

Back 53

two compounds are crystallized at the same time to produce a solid that is made up of stoichemetric amounts of each compound, with their structures paired together through attractive noncovalent interactions -hydrogen bonds.

Front 54

Grinding in mortar by pestle leads to..

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2 4,4bpe arranged parallel and separated by 3.7A and photocyloaddition can occur.

Front 55

Irradiation of co-crystals with UV light proudces...

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4,4-tpcb

Front 56

Compounds produced by plants are advantageous because..

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renewable resource, contain multiple functional groups that serve as handles for synthetic transformations, contribute sterogenic centers that might otherwise be costly to introduce

Front 57

biocatalysis

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transforms abundant compounds into more valuable ones

Front 58

Polysacarrhides consist of..

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numerous individual sugars attached via acetal linkages

Front 59

Characteristics of acetals

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derivatives of aldehydes which are stable under basic conditions but react with aqueous acid or alcohols and become protonated on oxygen converting them into hemiacetals and aldehydes.

Front 60

Benzoin condensation

Back 60

benzaldehyde reacts with cyanide ion to produce benzoin by carbon-carbon bond construction.

Front 61

umpolung

Back 61

reversal of polarity. Ex: original aldehyde C=O bond bears a partial positive charge on the same carbon which later becomes the carbanion bearing negative charge

Front 62

How is the benzoin reaction different than alkyllithium and Grignard reactions?

Back 62

Those two are destroyed by water. This reaction permits the presence of moisture and can be conducted in aqeous solution

Front 63

What is the biocatalyst used to carry out a Benzoin Condensation of furfural that forms a new carbon-carbon bond and produces furoin?

Back 63

Thiamine

Front 64

How to many analgesic work?

Back 64

inhibiting the cycloxygenase enzymes which are key to the biosynethesis of prostagladins.

Front 65

Prostagladins

Back 65

family of closely related cyclopentane compounds bearing two lipophilic tails. Involved in chemical signaling in number of biological processes such as stimulation of smooth muscle, lowering of blood pressure, induction of labor, increase of ocular pressure.

Front 66

Prostagladins association with pain?

Back 66

Mediate inflammatory response, so inhibiting their synethesis eliminates some of the pain associated with inflammation.

Front 67

NSAIDS

Back 67

non-steroidal anti-inflammatory drugs- acetaminophen, aspirin

Front 68

How is acetaminophen prepared?

Back 68

nucleophillic acyl substitution. Prepared from p-aminophenol and acetic anhydride.

Front 69

Bromine/ CCl4 Test

Back 69

Test for alkenes, positive test for unsaturation results in a discharge of the bromine color- decolorization of solution

Front 70

Flame test

Back 70

Test for aromatic compounds.

Black sooty smoke=aromatic.

Very long-chain alkane may give false positive. Rapid combustion=high oxygen content. Sparks=high nitrogen content.

Yellow smoke= aromatic, unsaturated, high MW aliphatic compounds.

Yellow non-smoky=lower MW aliphatic organic compounds.

Clear blue= oxygen rich compounds, ethanol

Front 71

Beilstein

Back 71

Test for alkyl or aryl halides.

Green color forms in flame= positive test for halogen, indicating the presence of chlorine, brome or iodine.

Front 72

Silver Nitrate Test

Back 72

Immediate ppt at room temp= benzylic, allylic and tertiary alkyl halides

Ppt upon heating= primary and secondary alkyl halides

No reaction= aryl and alkenyl halides

White ppt= Cl

pale yellow ppt= Br

yellow ppt= I

Silver- false positive for carboxylic acid

Front 73

Chromic Acid Test

Back 73

Test for alcohols.

Immediate appearance of blue/green color= primary or secondary alcohol

Remains orange= tertiary alcohols

False positive= aldehydes

Front 74

Lucas Test

Back 74

Test for alcohols.

Formation of ppt within 2 min= benzylic, allylic or tertiary alcohol

Formation of ppt after 10 minutes= secondary alcohol

No ppt= primary alcohol

Front 75

Ferric Chloride test

Back 75

test for phenols.

Most phenols produce an intense red, blue purple or green color.

False positives= esters and 1,3 dicarbonyl compounds

Front 76

Bromine water test

Back 76

test for phenols.

Phenol= disappearance of yellow bromine color, litmus paper turns pink

False positive= aromatic ethers

Front 77

DNP test

Back 77

test for aldehydes and ketones.

appearance of red orange or yellow ppt= aldehyde or ketone.

yellow ppt= non conjugated

orange/red ppt= conjugation

Front 78

Tollens test

Back 78

test for aldehydes and ketones.

silver mirror or black ppt= aldehyde

false positive= aromatic amines, phenols

Front 79

Iodoform test

Back 79

test of aldehydes and ketones.

pale yellow ppt= contains methyl ketone

false positive= ethanol and alcohols, acetaldehyde

Front 80

Sodium bicarbonate test

Back 80

test for carboxylic acids.

Bubbles= carboxylic acid

False positive= phenols bearing strong electron withdraing group, liquid aldehydes

Front 81

Hingsberg test

Back 81

test for amines.

Soluble in NaOH= primary amine

Insoluble in NaOH= secondary amine or tertiary amine

Front 82

Hydroxyl amine/ ferric chloride test

Back 82

test for esters.

Formation of deep red or purpose color= ester

False positive= phenols and carboxylic acids

Front 83

Iron hydroxide test

Back 83

test for nitro.

red-brown ppt w/in 1 min= nitro group

Front 84

Derivatives for alcohols

Back 84

phenyl urethane

3,5- dinitrobenzoate

Front 85

Derivatives for phenols

Back 85

phenyl urethane

3,5- dinitrobenzoate

brominated derivatives

Front 86

Derivatives for Aldehydes and ketones

Back 86

2,4- dinitrophenylhydrazone

semicarbazone

Front 87

Derivatives for carboxylic acids

Back 87

anilides and p-toluidides

amides

Front 88

Derivatives from esters

Back 88

Saponification of esters

Transesterifications- 3,5 dinitrobenzoates

N-benzylamides

Front 89

Derivatives from primary and secondary amines

Back 89

acetamide

benzamide

p-toluenesulfonamide

phenylthiourea

Front 90

Derivatives from Tertiary amines

Back 90

quaternary ammonium salt : methiodide

Front 91

molecular modeling/ computational chemistry

Back 91

calculating properties of molecules or compounds on a computer, provides useful predictions

Front 92

Bond order, aromaticity and substituents have strong effects on ?

Back 92

Bond strengths, energies and reactivities of molecules

Front 93

Resonance

Back 93

the averaging of electron distribution over two or more hypothetical contibuting structures to produce a hydrid electron structure

Front 94

What factors are important in evaluating the contribution each of the resonance structuresmakes to the actual molecule?

Back 94

^ # of covalent bonds in structure=stable

Formal charge seperation=unstable

^ E- neg of charge bearing atoms and charge density= unstable

Stability of a resonance hybrid is alway greater than the stability of any canonical contributor.

Front 95

Aromatic compounds

Back 95

planar cycle of sp2 atoms, the p orbitals of which are oriented parallel to each other. These overlaping p orbitals generate array of pi MO.

4n+2 electrons

Front 96

Tendency to favor substituion rather than addition suggest?

Back 96

Parent unsaturated ring system has exceptional stabilty- aromatic stabilization

Front 97

Carbonyl group stretching vibration

Back 97

strong, distinctive IR of 1710 to 1740

Front 98

Three factors that perturb carbonyl stretching frequency

Back 98

1- conjugation with a double bond or benzene ring lowers the stretching frequency

2-incorporation of carbonyl group in small ring (5,4,3) raises stretching frequency

3-changing an alkyl substituent of a ketone for electron donating or withdrawing group.

Front 99

Dipole moment

Back 99

degree of polarity and magnitude of the dipole is proportional to the difference in electronegativty or charge separation of the bonded atoms and the distance between these atoms

Front 100

Molecular complex

Back 100

assembly of two or more neutral molecules held together by non-covalent interactions ex. hydrogen bonds

Front 101

Hydrogen bond

Back 101

relatively strong non-covalent bond, attractive electrostatic interaction between polar molecules where at least one of the molecules has a hydrogen atom bound to an electronegative atom (O, F, N)

Front 102

Hydrogen bond donor

Back 102

atom that is covalently bound to hydrogen, highly electronegative and forms positive charge on hydrogen

Front 103

hydrogen bond acceptor

Back 103

has at least one lone pair of electrons

Front 104

Hydrogen bond distance

Back 104

distance between the hydrogen bond donor and acceptor. D-H :::: A. Distance is between D and A.

Front 105

Strentch of hydrogen bond

Back 105

inversely proportional to the length of the bond

Shorter bond is stronger

Front 106

electron donating substituent

Back 106

ex: methoxy group OCH3

makes more basic

weakens hydrogen bond

Front 107

electronegative substituent/electron withdrawing

Back 107

more acidic

strengthen hydrogen bond

ex: fluorine

Front 108

Stability of molecular complexes and bonding energy

Back 108

stronger hydrogen bonds, most stabilized, lowest in energy

Front 109

binding energy

Back 109

energy of complex - (energy of molecule 1 + energy of molecule 2)

Front 110

OH group stretching frequency

Back 110

intense and broad peak at 3550 -3200 cm

Front 111

IR spectra of hydrogen bondeed complexes

Back 111

stronger hydrogen bonds will exhibit weaker stretching frequencies and be shifted to the right in the IR spectrum.

weaker hydrogen bond will have stronger stretching frequencies and will be shifted to the left in the spectrum.