Topic 8 Review of Exam 5 New Molecule of the Week L-Tryptophan - - PowerPoint PPT Presentation

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Topic 8 Review of Exam 5

Chem 2312 Lecture for November 26, 2003 New Molecule of the Week

L-Tryptophan Serotonin Sleepy..sleepy...

Brain

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1.Which structure below is 3-aminopropanoic acid ii) Which structure below is N,N-Dimethylcycloheptylamine iii) Which structure below is 4-chloro-N-ethyl-3-nitroaniline iv) Which structure below is 2,2-Dimethyl-1,3-propanediamine

NH2 O OH O NH2 O H O NH2 H N OH O N N N NH HN NO2 Cl NH2 NO2 Cl HN NO2 Cl H2N NH2 N H H2N H N H N NH2 H2N

None of the above C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C1 C2 C3 C4 C16

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Provide a reasonable reaction mechanism (include lone electron pairs, charges, and curved arrows for all atoms involved in the reaction) for the formation of product BB starting with A1 and A2.

O

+

O O

OH

O O

A 1 A 2 BB H 2O

O

+

O O

OH

O O

A1 A2 BB

H H O H O O H O H H O O O H O O H H O O H O O H H O O O O H H H O O

4 Provide the structure of the major organic product(s) for 6 of the following 8 reactions If there are two or more major products show all of them.

O O

NaOCH 3/CH 3OH

O O O

• 1. NaOEt/EtOH, CH 3I
• 2. NaOEt/EtOH, CH 3CH 2Br
• 3. H 2O, NaOH
• 4. H 3O +/heat

N

1.

• 2. H 3O +

O Cl O O d

• 1. LDA
• 2. CH 3-CH 2-Br

a b c

O O d O O O O O O

H 3O +

5 Provide the structure of the major organic product(s) for 6 of the following 8 reactions If there are two or more major products show all of them.

NH O O

• 1. KOH
• 2. CH 3-CH 2-CH 2-Br
• 3. H 2N-NH 2

O Cl

• 1. HNEt2 (excess)
• 2. LiAlH 4
• 3. H 2O

Br

• 1. NaN 3
• 2. LiAlH 4
• 3. H 2O

N

• 1. Heat

e. f. g. h.

H 2N N NH 2

+ HO -

6 Provide a synthetic pathway for DD starting with CC as shown below. Develop your synthetic scheme so as to maximize formation of DD with as few steps as possible. Describe all reagents, reaction conditions needed, and intermediate chemical structures formed due to proposed chemical reactions

O NH2 NH2

CC DD

O NH2 NH2

CC DD

O NH2 Cl

AlCl3 NaOH, Br2

O N H Br NH2

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O O O O FeBr3/Br2 Br O O Br + Which Ring Will Be Attacked? 15.34 15.35 O NH O O FeBr3/Br2 Which Ring Will Be Attacked? O FeBr3/Br2 Which Ring Will Be Attacked? FeBr3/Br2 Which Ring Will Be Attacked? O Br O Br + H N O Br H N O Br + O O Symmetrical Br

REMEMBER>>>>Problem from Solomoms and Fryhle Why Not other Ring??

8 Identify the reagent(s) and conditions required to transform the following starting materials into the corresponding products for the reactions described below.

O H N i

1 H2N-Et (excess) 2 LAH or H2/Pt

O OH NH2

ii

1 SOCl2 2 KN3 3 Heat 4 H2O

9 Identify the reagent(s) and conditions required to transform the following starting materials into the corresponding products for the reactions described below.

O O O

iii 1 NaOEt/EtOH 2 H-C(O)-OEt 3 H2O

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Determine the order of BASICITY for the following aniline derivatives shown below, please place answer in the adjacent box.

Answer I: A1(most basic) > A2 > A3 (least basic) Answer II: A3(most basic) > A2 > A1 (least basic) Answer III: A1 (most basic) > A3 > A2 (least basic) Answer IV: A3 (most basic) > A1 > A2 (least basic) Answer V: A2 (most basic) > A1 > A3 (least basic) Answer VI: A2 (most basic) > A3 > A1 (least basic) Answer VII: none of the above

NH2 NH2 NH2 CH3 CH3 Cl NO2 NO2

A1 A2 A3

Please justify your selection of the Most basic and Least Basic compound for 6a: In general, the more electron density on the N of aniline the stronger a base, for A1 their are 2 electron donating groups on the aromatic ring which will put greater electron density on N; for A3 this aniline derivative has 2 electron withdrawing groups (Note: electron with drawing ability of NO2>> Cl) that remove electron density from the N thereby reducing its electron density/basicity

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Determine the order of BASICITY for the following nitrogen compounds shown below, please place answer in the adjacent box (4 marks).

Answer XI: B1(most basic) > B2 > B3 (least basic) Answer XII: B3(most basic) > B2 > B1 (least basic) Answer XIII: B1 (most basic) > B3 > B2 (least basic) Answer XIV: B3 (most basic) > B1 > B2 (least basic) Answer XV: B2 (most basic) > B1 > B3 (least basic) Answer XVI: B2 (most basic) > B3 > B1 (least basic) Answer XVII: none of the above

NH2 O NH2

NH3 B1 B2 B3

What is the hybridization of the N in B1:____sp3_______ What is the hybridization of the N in B2:____sp2_______ sp2 hybridized nitrogen atom is found in an amide functional group.

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• ne week

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Please Remember

Fall 2003 Finals Schedule http://www.oscarweb.gatech.edu/fall/oscar/ finals.html Final exams are given in the lecture hall that you used during the semester. Class MWF 1:00>> Exam Period 4 Exam Date TUES:12/9 8:00-10:50 am