118 c Fall 15 Final Full

7/25/2019 118 c Fall 15 Final Full

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Chemistry 118C

Fall 2015

Final

Thursday Dec. 10th

, 2015

Instructor: Lievens

This exam contains eleven (11) pages and twelve (12) problems. Please make surethat your copy contains all eleven (11) pages. If there is a problem, please tell the exam

administrator prior to beginning. Please answer all questions. Remember that UCDavisCode of Academic Conduct applies to this exam and all other graded work in this class.

Please no calculators, notes, books, models, or other aids and remember to turn off cellphones.

Name:________________________________________________________________

Last First MI

Student ID. # __________________________________________________________

T.A./ Lab Section: ______________________________________________________

Page # Points Page # Points

2 7

3 8

4 9

5 10

6 11

Total

(295)


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1. Reactions: (24 pts). Draw the structure of the expected organic product(s) formedin the following reactions including correct stereochemistry. If the product is

racemic write both isomers or write racemic. Assume all reagents listed arepresent in excess unless otherwise noted. If no reaction occurs, state No

Reaction.

A)

B)

C)

D)

E)

F)

1) NaN3

2) Pd, H23) CH3I (xs)

Br2, PBr3(cat).

CHO

OHH

OHH

CH2OH

Br

OH

O

HHO 1) HCN

2) Pd-BaSO43) H2O

O

OH

HO

OH

OH

OH

CH3CH2OH,

HCl (cat.)

CN 1) (CH3)2CHCH2CH2Li

2) H3O+

O

O1) DIBAL-H

2) H2O


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Reaction.

NH2

1) NaNO2, HCl, H2O 0oC

2)

G)

H)

I)

J)

K)

L)

Cl

HHO

OHH

CH2OH

HNO3, H2O

N

OHH

CHO

1) NaOH, heat, pressure

2) H3O+

S S

1) CH3CH2CH2CH2Li

2)

3) HgSO4, CaCO3, H2O, CH3CN

O

O

OCH3

O 1) NH3, CH3CH2CH2CHO

2) HNO33) KOH, H2O

4) CaO, Heat

OOH

OH

HO

OH OH

O

O O

pyridine

(xs)


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Reaction.

1) KMnO4, NaOH, H2O

2) H3O+

3)CH3CH2OH, H2SO4

H3CH2CO OCH2CH3

O O 1) NaOCH2CH3, CH3CH2OH

2)

3) H2SO4, H2O, heat

1) NaOCH2CH3, CH3CH2OH

2) H3O+

M)

N)

O)

P)

Q)

R)

Br2, H2SO4, SO3

O

H

1) NH3,2) HCN

3) H2SO4, H2O, heat

O

N

O

O

OH1) Jones reagent

2)

OH

O

, heat


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4. Mechanisms: (25 pts). Show the detailed reaction mechanism for each of thefollowing reactions. Include the structure of the expected products and all relevant

resonance structures.

H

O NS

RNaOH,

What is the name of this reaction? __________________________________

What is the pKa of the catalyst? ____________________________________

The organic intermediate is a _________________________ anion.


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5. Synthesis: (36 pts). Show how you would carry out the following syntheses.Include the reagents you would need for each step and the structure of the

intermediate products formed in each step. You may use any inorganic reagentsyou need and organic reagents of seven or less carbons.

HN

O

OA)

O

OH

O

OH

Br N

O

B)


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6. Vocabulary: (40 pts.) Fill in the blanks with the appropriate vocabulary word. Iftwo words are given circle the correct one.

A) The commonly occurring amino-acids used in protein synthesis are D / L amino-acids

they are always / sometimes / never S stereocenters and have the amino group on the

ipso / alpha / beta / other carbon.

B)

In general an amide (CONHR) proton shows up between 0.5 5.0 / 2.0 2.5 / 3-4 / 6

8 / 10 13 in the1H NMR, and an nitrile (-CN) shows up between 10 35 / 65 85

/ 110 126 / 165 185 / 195 210 ppm in the13

C NMR.

C) Rank the given functional groups from highest to lowest IUPAC priority:

ester, amine, alkene, alcohol, ether

____________> ____________ > ____________> ____________ > __________

D) Resonance between the carbonyl and leaving group in carboxylic acid derivatives

increases with large / small atoms as the leaving group due to __________________,

and increases with strongly / weakly electronegative atoms due to

____________________. Increased resonance with the leaving group will increase /

decrease acidity at the enolate position and increase / decreasebasicity of the

carbonyl lone pair.

E) The secondary structure of a protein consists of ________________ and

_______________ structures and is held together by _________________ between

atoms in the side chains / backbone, while tertiary structure is held together

by_________________ between atoms in the side chains / backbone. Both are easily

disrupted by: ________ or ________ or ___________.

F) Ethyl acetoacetate has a pKa of about ___________ at the _____________, which is

more / less acidic than ethyl propionate. The conjugate base of ethyl acetoacetate

generally adds 1,2- / 1,4-to Michael acceptors and always / sometimes / never

undergoes a Robinson annulation.

G) Claisen rearrangements occur with an ether that has both an _________ and a

__________ group.

H) True / False Phenols are stable enols, so can tautomerize to carbonyls as the

intermediates in certain reactions.

I) True / FalsePhenols are often made by electrophilic aromatic substitution of benzene

with HO

+

.J) Treatment of aniline with NaNO2, HCl, and H2O initially forms the ______________

functional group, which decomposes to an ______________ functional group that can

be used as a nucleophile / electrophile / reducing agent / base, and which is more /

less stable than the same functional group with an alkyl group instead of an aromatic.

K) Reaction of a carboxylic acid with alcohol and acid is a ___________________

reaction and uses a _________________ mechanism


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7. Amino-Acids:A) Calculate the pI of each of the given amino acids (6 pts)

H3NOH

O

H3NOH

O

H3NOH

O1.8

9.2

2.29.0

9.6 1.9

3.7

Compound B

Compound ACompound C

10.5

NH3

O OHHN

N H 6.2

B) Sketch the major form of compound C from question 7A in a solution at the given

pH (8 pts)

pH 1 pH5 pH 8 pH 11

8. Structure: (8 pts) Draw the alpha and beta anomers of the furanose and pyranoseforms of D-fructose in the appropriate blanks.

HHO

OHH

OHH

CH2OH

!"furanose

#"furanose

!"pyranose

#"pyranose

D-fructose

CH2OH

O


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10.Nomenclature: (12 pts.). Give the proper (IUPAC) chemical name or draw thestructure of each of the following compounds. Include stereochemistry where

appropriate.

A)

B)

C)

D)

E)

F)

HO

O

NH2

O

O

NH

OHO

NH

O OH

4-(N,N-dimethylamino)-2-ethylphenol

11.pKa:(13 pts). Using the letter codes provided rank the two series of compoundsfrom best acid to worst acid.

OH OH OHOH OHOH

N

H

N

H H

NH3

N

H

H

H

OCH3CN

CN

N

H

N

H

NH2

O

> > > >>

~ > > > >>

A B C D E F

M N O P Q R S

best acid worst acid

best acid worst acid


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12.Spectroscopy: (20 pts.) The unknown compound A(C16H25NO3) gives thefollowing proton and carbon NMR spectra. Significant IR peaks were also

observed.What is compound A?

8 7 6 5 4 3 2 1

200 150 100 50 0

IR: !3256 (broad), 2947, 1740, 1209 cm-1

.


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118 c Fall 15 Final Full

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