Org Chem

Question 1

Epimer

Answer 1

Type of diastereomer where only one chiral center is the opposite configuration in the pair of epimers

Question 2

Anomer

Answer 2

Type of epimer where the anomeric carbon in the sugar is opposite configuration - carbon 1

Epimers that form as a result of ring closure

Question 3

Mutarotation

Answer 3

Equilibrium between anomers

Question 4

Pyranosee vs furanose

Answer 4

6 ring vs 5 ring sugar

Question 5

Meso compund

Answer 5

Internal plane of symmetry

Question 6

Enantiomer

Answer 6

Mirror images

All chiral centers are opposite

Question 7

Geometric isomer

Answer 7

Cis trans isomers or E Z

Question 8

Constitutional isomers

Answer 8

Same formula

Question 9

Conformational isomers

Answer 9

Different spatial arrangement

Question 10

Difference between cis tans and EZ

Answer 10

Cis trans - same groups on same side for cis

E Z - highest priority groups on same side is Z

Question 11

Lipid bilayer membrane fluidity

Answer 11

Cholesterol
Unsaturation
Shorter tails

Question 12

Steroids

Answer 12

Tetracyclic

Question 13

Glycogen

Answer 13

Alpha glucose monomers connected by 1,4 or 1,6 glycosidic linkages

Question 14

Lactose

Answer 14

Galactose + glucose

Beta 1,4

Question 15

Sucrose

Answer 15

Glucose + fructose

Question 16

Reducing sugar

Answer 16

Carbs that can be oxidized by benedicts test

Aldehydes, ketones, hemiacetals

Question 17

Gabriel malonic ester synthesis

Answer 17

Phthalimide + KOH -> phthalimide ion + malonic ester -> Phthalimidomlomic ester which can become all types of amino acid

Question 18

Strecker synthesis

Answer 18

Racemic amino acids produced (unlike stereochemically pure L amino acids)

Uses cyanide and ammonium on aldehydes

Question 19

Sn2 mechanism

Answer 19

1 step
Stereochemical inversion
Strong nucleophile
Favored by low substitution of groups
Weak leaving group
Rate law includes nucleophile and electrophile
Polar aprotic solvent (non H bonding)

Question 20

Sn1 mechanism

Answer 20

2 steps
Strong leaving group
Weak nucleophile
Rate law includes electrophile 
Favored by high substitution of groups
Protic solvents

Racemicization

Question 21

Oxidation of primary alcohol

Answer 21

Aldehyde via PCC

Question 22

Oxidation of secondary alcohol

Answer 22

Ketone via CrO3

Question 23

Alpha vs beta protons

Answer 23

Alpha are next to the carbonyl

Beta are one further

Question 24

Nucleophilic Addition to aldehydes and ketones

Answer 24

Require reducing agent like NaBH4 to provide hydrogen

Question 25

Grignard reaction

Answer 25

Require grignard reagent and acid workup Produces MgBrOH

Question 26

Cyanohydrin formation

Answer 26

Aldehyde or ketone + cyanide ion as nucleophile

Question 27

Imine formation

Answer 27

Aldehyde or ketone + primary amine forms imine

Question 28

Enamine formation

Answer 28

Aldehyde or ketone + secondary amine

Question 29

Aldol condensation Crossed aldol?

Answer 29

Enol + keto -> hydroxyaldehyde (ketone and hydroxyl without double bond of an enol) Requires strong base like NaOH Enol and keto groups from diff carbonyl compound

Question 30

Reduction of carboxylic acid

Answer 30

To go to primary alcohol must use LiAlH4 and not NaBH4

Question 31

Transesterification

Answer 31

Involve ester and alcohol

Question 32

Saponification

Answer 32

TAG is hydrolyzed to glycerol and 3 fatty acids

Question 33

Synthesis of acid halides

Answer 33

Carboxylic acid + SOCl/PBr3

Question 34

Acid anhydride formation

Answer 34

Two carboxylic acids

Question 35

Relative reactivity of CA derivatives

Answer 35

Acid chloride Acid anhydride Esters Amides

Question 36

Extractions

Answer 36

Can add acids to convert amines into ions dissolvable in aqueous phase Can add bases to convert carboxylic acids into salts dissolvable in aqueous phase

Question 37

Deshielding means

Answer 37

Electron cloud is more distorted away from the atom

Question 38

NMR

Answer 38

Downfield is more deshielded

Question 39

L vs D sugar

Answer 39

If hydroxyl of highest numbered chiral carbon is on the left, then it’s an L

Question 40

Carboxylation

Answer 40

Addition of COOH