!1!CHE 230 Organic Chemistry 1 Exam 2 March 9, 2011 Name: Student number: Before you begin this exam: First: You are allowed to have a simple model set and a calculator at your seat. Please put away all other materials. Second: Place your student identification on your desk. A proctor will come around to check everyone’s ID. Third: Read through the entire exam. Your goal, as always, is to score as many points as possible. Do not waste time on problems that you can’t do if there are others that look easy. Fourth: READ EACH QUESTION CAREFULLY. Be sure you answer the question that is asked. Fifth: This exam must be turned in by 9:50 AM SHARP. There will be no extensions, so budget your time carefully. !! 1.! 8!points! ! !!!! 2.! 6!points! ! !!!! 3.! !!8!points! ! !!!! 4.! 10!points! ! !!!! 5.! 16!points! ! !!!! 6.! !!5!points! ! !!!! 7.! 12!points! ! !!!! 8.! !!5!points! ! !!!! 9.! !!6!points! ! !!!! 10.! 24!points! ! !!!! 11.!! 5!points! ! !!!!!!!! ! 100!points! ! !!!!2!1.! (8!points)!!Assign!the!E,#Z9!configuration!to!all!4!of!the!double!bonds!in!leukotriene#B4.!!!!!CO2HOHOH!! ! LTB4#!!!2.! (6!points)!!Predict!the!hybridization!of!the!indicated!atoms.!!!! !!!!! !! ! !!!!!3.! (8!points)!!In!the!compounds!below,!put!a!star!(or!some!other!mark)!at!each!stereogenic!center.!!Be!certain!that!it!is!clear!w hich!atom(s)!you!are!marking.!!!HNO O!O NHOH! !NHOCH3HOONH2OO!## # Methylphenidate## Propranolol# # # Nutrasweet## # (Ritalin)# (Meier’s#anti@hypertension#drug)#!!!NHCH3OHHOOCH3H H!3!4.! (10!points)!!Assign!the!absolute!configuration!(R!or!S)!to!the!indicated!stereogenic!centers.!!!OOOClOHOHOHClClHOOHSplenda! ! !OHHOOHHHOHOHHHOH! D@Allose!!!!5.! (16!points)!!What!is!the!structural!relationship!within!each!pair!of!structures?!!Determine!whether!they!are!skeletal!isomers,!conformers,!enantiomers,!diastereomers,!or!identical.!!CO2HCO2HCO2HCO2H!!OHHOHHOHHOHHOHOHOOHHHHOHOHOHHHOH!!!These!are:! ! ! ! ! These!are:! ! ! ! ! !!!!H2NOHOH2NOHO! ! !Ph Ph Ph Ph!!!These!are:! ! ! ! ! These!are:! ! ! ! ! !!!6.!! (5!points)!!For!the!cation!below,!determine!the!number!of!π9molecular!orbitals!and!determine!if!the!ion!is!aromatic!or!anti9aromatic.!!! ! !! !!!!!!!!!!! #!π9molecular!orbitals!!! ! !!! ! Aromatic!or!antiaromatic!!! ! ! !H!4!7.! (12!points)!!For!each!of!the!compounds!below,!determine!whether!it!is!aromatic,!antiaromatic,!or!neither.!!!!! ! ! ! ! ! ! ! ! ! ! ! !!!!8.! (5!points)!!The!DNA!nucleotide!base!cytosine!is!shown!at!the!right.!!This!compound!is!aromatic,!meaning!that!it!meets!all!criteria!for!aromaticity,!including!Hückle’s!Rule.!!In!the!space!provided!below,!draw!a!resonance!form!!(not#the#hybrid)!of!this!molecule!in!which!the!69electron!aromatic!π9system!is!evident.!!!!!!!!!!!!!9.! (6!points)!!The!DNA!nucleotide!base!adenine#!is!shown!here.!!For!the!nitrogen!atoms!indicated!with!arrows,!determine!what!orbital!houses!the!lone!pair!of!electrons.!!!!!NNNHNNH2!!! NNHNH2O!Cytosine#!5!10.! The!mass!spectrum!and!the!IR!spectrum!for!a!small!organic!compound!are!given!below.!!Consult!this!data,!then!answer!the! following!questions.!!! a)!!(4!points)!!What!is!the!molecular!weight!of!the!compound?!!!! b)!!(6!points)!!Provide!three!viable!molecular!formulae!for!the!compound:!!!! ! i)!!! ! ii)!!! ! iii)!! !!! c)!!(5!points)!!What!is!a!likely!structure!for!the!m/e!=!43!fragment!in!the!mass!spectrum?!!!!!!Mass!spectrum!for!problem!10:!!! !!6!! d)!!(4!points)!!List!two!structural!features!(functional!groups)!that!you!can!identify!in!the!IR!spectrum,!and!list!the!vibrational!bands!(peak!positions,!in!cm91)!that!suggest!those!group.!!! ! i)!!!! ! ii)!!!!IR!Spectrum!for!problem!9:!!! !!!! e)!!(5!points)!!Draw!the!most!viable!structure!of!the!compound!that!produced!these!spectra..!!!!7!11.! (5!point!bonus!question)!How!many!stereoismers!are!possible!for!prostaglandin!F2α!(shown!below)?!!(Careful!!!This#is#harder#than#it#looks…)#!CO2HHOHOHO!# #
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