Chem3BPracticeExams

Chem3BPracticeExams - 1 EXAMINATION 1 Chemistry 3B Name:_...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
1 EXAMINATION 1 Chemistry 3B Name:__________________________ SID #:______________________ Print first name before second! Use capital letters! Peter Vollhardt February 23, 2006 Please provide the following information if applicable. Making up an I Grade _____ (If you are, please indicate the semester during which you took previous Chem 3B: ––––––––––––––– –––––––––––– Semester Instructor Please write the answer you wish to be graded in the spaces provided. Do scratch work on the back of the pages . This test should have 17 numbered pages. Check to make sure that you have received a complete exam. A good piece of advice: Read carefully over the questions (at least twice); make sure that you understand exactly what is being asked; avoid sloppy structures or phrases. It is better to be pedantic in accuracy now than sorry later! Good Luck ! DO NOT WRITE IN THIS SPACE I. ______ (30) II. ______ (30) III. ______ (50) IV. ______ (50) V. ______ (40) VI. ______ (30) VII. ______ (20) Total: (250)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 I. [30 Points] Name or draw, as appropriate, the following molecules according to the IUPAC rules. Indicate stereochemistry where necessary ( cis , trans , R , or S ). a. I Br CHO b. O c. R -4-Methyl-2-cyclohexenone d. Meta -(1-methylethyl)(methoxymethyl)benzene
Background image of page 2
3 e. II. [30 Points] 1-Methylthio-4-nitrobenzene A undergoes preferential electrophilic attack by E + to give only one of the two products shown. NO 2 SCH 3 1 2 3 4 E + -H + NO 2 SCH 3 E or NO 2 SCH 3 E A a. Which one? Mark the box below your choice with an X. b. Write the resonance forms of the intermediate formed on attack of E + at: C-2: Four resonance forms
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 C-3: Three resonance forms c. Circle (in your answers above): a. the most strongly contributing resonance form of the attack at C-2 and b. the least contributing resonance form of the attack at C-3. III. [50 Points] Add the missing components (starting materials, reagents, or products) of the following reactions in the boxes provided. Aqueous work-up (when required) is assumed to be part of a step. It is not part of any answer. a. + HCl Thermodynamic product b . Δ A cyclobutene H 3 C H 3 C CH 3 OCH 3
Background image of page 4
5 c. + CN CN d. h ν H H A hexatriene isomer of product. e. K + - OC(CH 3 ) 3 CH 3 CH 3 13 C NMR: 7 lines A salt; 13 C NMR: 4 lines f. NO 2 OCH 3 Cl SO 3 ,H 2 SO 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 g. OH OH CH 3 CCH 3 O H + -H 2 O + 13 C NMR: 4 lines h. Cl, AlCl 3 O 1. 2. Zn(Hg), HCl, Δ i. 1 . P ( C 6 H 5 ) 3 2. CH 3 Li 3 . O I
Background image of page 6
7 j. H 2 NNH 2 , Δ , and O IR Spectrum of product : A hydrocarbon 4000 3000 2000 1500 1000 500 cm -1 IV. [50 Points] Treatment of acetal A with conc. nitric acid and H 2 SO 4 led to unknown B. The IR and NMR spectra of this product are shown below. HO H O O HO 3 S B (unknown) 1. HNO 3 , H 2 SO 4 2. H 2 O, H + , Δ A
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8 a. After consideration of the spectral data, write the structure of the product in the box below. Structure of unknown b. Interpret the spectral data as requested in the spaces provided. 1. IR Spectrum Confirm or rule out the presence or absence (circle one) of the following bonds. Enter an approximate expected stretching frequency in the box.
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 238

Chem3BPracticeExams - 1 EXAMINATION 1 Chemistry 3B Name:_...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online