organic chem

Part A. Multiple choice questions: please circle the right answer (1 pts X 12 =24 pts total)

(1) The distinction between a saturated hydrocarbon and an unsaturated hydrocarbon relates to

a) boiling points. b) flammability. c) number of carbon atoms present. d) types of carbon-carbon bonds

present

(2) How many carbon atoms are present in the alkane whose IUPAC name is 2,2,4,5-tetramethylheptane?

a) five b) seven c) eight d) eleven

(3) Cis-trans isomerism is possible for which of the following alkenes?

a) CH2=CH–CH2–CH2–CH3 b) CH3–CH=CH–CH2–CH3 c) CH3–CH=CH2 d) CH2=CH–CH2–CH3

(4) Oxidation of a secondary alcohol produces a(n)

a) ketone. b) aldehyde. c) carboxylic acid. d) ether.

(5) Comparison of the boiling points shows butanol (C4H9OH) has higher boiling point than

diethyl ether (C2H5OC2H5). The reason is a) Butanol has hydrogen bonds b) Mass of butanol higher than diethyl ether. c) Butanol has higher London dispersion force than diethyl ether. d) No correct answer.

(6) Which of the following statements concerning the structure of the functional group

present in carboxylic acids is incorrect? a) Two oxygen atoms are present. b) A carbon-oxygen single bond and a carbon-oxygen double bond are present. c) A carbon-hydrogen bond is present. d) An oxygen-hydrogen bond is present.

(7) Primary alcohol may be converted to carboxylic acids by reacting them with

a) a strong base. b) a strong acid. c) a strong oxidizing agent. d) a weak oxidizing agent.

(8) IUPAC name for acetylene is (CHºCH) a) Ethyne b) Ethene c) Methyne d) Methelene

(9) Amines have basic properties because of the presence of

a) a hydroxyl group in such compounds. b) an unshared pair of electrons on the nitrogen atom. c) a positive charge on the nitrogen atom. d) the ability of the nitrogen atom to give up hydrogen atoms.

(11) Inversion of configuration happens when the reaction follow a ________ pathway. a) SN1 b) SN2 c) E1 d) E2

(12) A lipid is any substance of biochemical origin that is mostly nonpolar. Do you think it would be

a) soluble in water, but insoluble in nonpolar solvents. b) insoluble in both water and nonpolar solvents. c) soluble in nonpolar solvents but insoluble in water. d) None of the answer is correct.

Part B. Answer the following questions

1. Determine the R / S configuration of the following compounds. Write the priority of the groups. (2pts X 4 = 8 pts) .

2. Determine what type of isomers are the following pairs of compounds. (2pts X 4 = 8 pts)

3. Which of the following alkenes shows cis-trans isomerism? (2pts)

(a) (b) (c)

(d)

(e)

4. What are the situations when molecule/ molecules will not show optical activities even a chiral center is present in the molecule/ molecules? Give examples. (4 pts)

5. For each of the stereochemical descriptions on the left, select from the response list on the right an appropriate set of structural formulas. Responses on the right may be used more than once or need not be used at all. (2pts X 3 = 6 pts ) (i) Enantiomers _________ (ii) Diastereomers ________ (iii) Epimers __________

CHO

OH

CH2OH

H OH

H

CHO

HO

CH2OH

HHO

H

anda)

CHO

OH

CH2OH

H OH

H

CHO

H

CH2OH

HHO

OH

andb)

CHO

OH

CH2OH

H OH

H

CHO

H

CH2OH

OHHO

H

andc)

CHO

OH

CH2OH

HO OH

H

CHO

H

CH2OH

OHH

OH

andd)

Part C: Nomenclature

1. Give the IUPAC name for each of the following: (2 ptx6 =12 pts)

(a) (b) (c)

(d) (e)

CH2CH2CH

CH3

CH2CH3

CH3

CH2

CH3

CH C CH2

CH2

CH2 CH2 CH3

CH3 CH3

CH2

CH3

CCHCH

CH3

CH3

CH3

CH3

CH3

Cl

CH3

(f)

2.Draw structures of each of the following IUPAC or common names: (2ptx5= 10pt total) i) 2 Methylcyclohexanol

ii) 2, 4-Dihydroxypentane

iii) 3-Chloro octan -2,4,6 –triene

iv) 2-methyl heptan-1-ene-3yne

v) 3-Bromo-2 chloro hexan-1 ol

3. The following compound is Penicillin , a common antibiotic.

Circle and name ALL of the functional groups in this compound. (3 pts) Part D: REACTIONS: Fill in the boxes: (2pts X 12 = 24 pts) 1.

2.

3

4. .

5.

6.

7. CH3CH2CH2COOH + CH3CH2OH 8.

9.

10.

11.

12.

Conc. H2SO4

Part E Synthesis :(Total points 20) How will you synthesize the compounds from the given starting compound? Write the reagents and reaction conditions in each step ( 5pts +5pts = 10 pts ) 1.

2.

2. Write the structure of an alkyne with at least 3 carbon atom (1pt) If you use this alkyne as your starting material, write reactions by which you can synthesize

i) Primary alcohol with 3 carbon atoms. (write all the steps and reagent for each

step)(3 pts )

ii) Secondary alcohol with 3 carbon atoms (write all the steps and reagent for each step)(3 pts )

Bonus question: (6) 1.Write at least two possible structures for the molecular formula C5H8Cl2 (3pts)

2.How many chiral centers are there in the structure cholesterol? (3pts)