LAST NAME FIRST NAME UTEID Instructions This exam will be closed book No notes books calculators or molecular models will be allowed The exam will be comprised of two distinct parts Part I will consist of a series of multiple choice questions Your answers to these questions must be submitted on a Scantron bubble sheet The answer sheet will be provided for you but you will need your own 2 pencil s Only answers marked on the bubble sheet will be graded Answers to Part I questions marked on the exam itself cannot not be graded No re grades will be possible on Part I of the exam Part II consists of questions for which you will need to write out your answers using structures and or words This part of the exam will be hand graded Answers for the Part II questions that are written in pencil will not be eligible for re grades Answers written in pencil with ink overlay will not be eligible for re grades If you use a pen to answer the Part II questions only blue or black ink is acceptable Answers written in red ink cannot be graded 1 You must have your valid UT ID card or other government issued ID with you You will need to show it to the proctors when you turn in your exam 2 Chapter 4 of the University s General Information catalog outlines this university s policies regarding exams as well as other quizzes administered during the semester Specifically students are expected to remain in the exam room until a test is completed These policies will be strictly enforced with no exceptions You may not leave the room for any reason until you are ready to turn in your exam If you wish to leave the room you will need to turn in your exam to the proctors and you will not be allowed to return Please plan accordingly by using the rest room before the exam starts CH 320 N Exam 3 Question 1 2 3 4 5 6 7 Section II Value 10 18 16 14 12 12 8 90 Section I Raw Total 60 150 Grade Score ID A 320N XM3 Answer Section MULTIPLE CHOICE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ANS ANS ANS ANS ANS ANS ANS ANS ANS ANS ANS ANS ANS ANS ANS D D A D C B B C A C C D C B B PTS PTS PTS PTS PTS PTS PTS PTS PTS PTS PTS PTS PTS PTS PTS 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 1 UTEID CH 320 N EXAM 3 KEY PART 2 Free Style Answer Format 90 pts in this section 1 Reactions Provide the products for the following reactions Regio and stereochemistry must be clearly drawn in the products 10 pts 2 pts per box H O H O H O O H O O O Must show cis O O CO2Et CO2Et CO2Et CO2Et CO2Et CO2Et Must show cis CO2Et CN EtO2C NC CN CO2Et CN CO2Et Must show trans Must show trans 8 UTEID CH 320 N EXAM 3 KEY 2 Mechanism Provide a mechanism for the following transformation Show all important flows of electrons charges and intermediates Where indicated in the structure n a box draw the intermediates 18 pts 3 pts per box Allow partial credit O O H OH dehydrate OH O OH H deprotonate proton transfer O H O OH O O make a bond O H int these are C C bond f orming reactions make a bond O H2C O O H OH OH H proton transfer O H2C deprotonate O 9 UTEID CH 320 N EXAM 3 KEY 3 Texas two step Provide both the reagents in square boxes and the product rounded box for these synthesis Note that a second reagent may be required in the square boxes For example the acid step of a Grignard addition In the rounded rectangle draw the structure of the compound from the first reaction 4pts per Scheme 16pts Scheme 1 Scheme 2 Scheme 3 Scheme 4 Grading Guide 1 pt reagent box 2 pts product box 10 UTEID CH 320 N EXAM 3 KEY 4 Multi step synthesis Provide the products for the following conversions You must include any stereo and regiochemistry in your structures 14 pts 2 pts per box O O OR O 1 CH3CH2CH2Br OCH3 OCH3 2 H2O OCH3 LDA O THF 78o C Draw the correct enolate OCH3 O O O O 1 CH3CO2CH3 NaOCH3 OCH3 CH3OH OCH3 OR OCH3 2 H2O Draw the correct enolate 1 NaOCH3 CH3OH 2 PhCH2Br O O O O OH CH2Ph CH2Ph 11 1 NaOH 2 H3O O OCH3 CH2Ph UTEID CH 320 N EXAM 3 KEY 5 Multi step synthesis Provide the products for the following conversions You must include any stereo and regiochemistry in your structures 12 pts 3 pts per box 6 Multi step synthesis Provide the reagents for the following conversions Note that some transformations will require more than one chemical step e g the acid step of a Grignard reaction 12 pts 3 pts per box O O 1 NaOCH3 Ph OCH3 Ph Ph 1 NaOH 2 H3O O Ph Ph 3 2 H3O CO2CH3 1 LDA 2 CH3CH2Br 3 H2O O NHCH3 Ph CH3NH2 Ph H2 Ni 12 Ph Ph UTEID CH 320 N EXAM 3 KEY 7 Mechanism Provide a mechanism for the following transformation Show all important flows of electrons charges and intermediates Where indicated in the structure n a box draw the intermediates 8 pts O O Ph CH3 Deprotonate OH Must show some method of deprotonation to form the correct enolate O O H2C O H2C O Ph O Ph Ph This is OK too Break a bond Make a bond Make a bond OH O H OH Add a proton H HO O Ph Ph 2 pts per step END OF EXAM SECTION 13 O