Spring 06 Exam 4 Blank - CHEMISTRY 225 TEST #4 JUNE 9, 2006...

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Unformatted text preview: CHEMISTRY 225 TEST #4 JUNE 9, 2006 l. (25) 2. _ (13) NANIE 3. (23) Useful etemie numbers: H =11 C = ELN = 7, 0 m 3, Si = 14, C1 = 1?, Br: 35 4. (14) TOTAL (75) GOOD LUCK! 1. (25 Peints) STEREOCHEMSTRY IN CYCLIC AND ACYCLIC MOLECULES. a. ( I 12) Chemists in Bereeienn, Spain have reeently sneeeeded in synthesizing the twe enentiemers ef the nevel amine eeid 3- ehiereleneine [F‘etrehedren Lent 2006,, 47, 3701]. The streeture ef ene ef these twe ennntiemers is shew te the right in jagged line fermet. I (4) Determine the ehseinte eenfignrntiens at the twe stereegenie esrhens ef 3-eh1ere1eneine. ( 2 , 3 ) I (4) Cenvert the meleeule te e Fiseher prejeetien with C(i) at the tept I (4) Write Fiseher prejeetiens fer the ensntiemer and e diestereemer ef this meleenle. ('3H(CH3)2 eriginal meleeule the enantiemer a diastereerner 2 b. ( f 8) Dccsyribcuse, structure belmv, is the sugar cempeneut cf DNA. I (3) Cyclic sugars are nften depicted by means cf a Hawarth prejectien in which the structure is viewed edgevnn. Ccrnplete the Havvmth pmjecticn cf deuxyribese by adding grcups and hydrcgcn atnrns in the apprcpriate lecatiuns en the structure. OH '- HO“ | deux fibuse m y Hawcrth prcjecticn +- (S) Pram the menu cf structures belew select the letter ef the muleculc that matches the descripticn. A letter may be used mere than cnce er net at all. 9H OH OH QH OH WON HO.._ <0l I. (CK INOH HO O i 1.. 507m 'bH OH Ho” i’OH H0 A B C D E van alternate representatiun crf denavribcse. _ -the enanticmer cf deuavribese -a structural isumer cf deuxyrihcse __I r__ -twc~ diastcreumers cf dem-tyrihcse m? and c. [ f 5) chu may recall frum Test #3 that 2:3-butanediul L can exist in three stereeisemeric farms. A structure fur the mesa H3C\ (uptically inactive) farm cf 2:3-butanedicl is shuwn te the right. C 0/ .OH - (2) Ccnvert mesa-2,3-bu’tancdinl tu a Fischer prujecticn. H: / \ HO . I (3) Write jagged iinefurmalus fur the tvvc uptically active farms uf CH3 2:3 -butancdiul. mean—213—butanediul — uptically active stereuiscmers Fischer prcjecticn b. if f 7) The bigth substituted cyclchexane derivative pinitul | (planar prejectiun fennula tn the right) was used as a chiral building bleck fur a recent synthesis cf the anticancer drug (+)-paneratistatin [Tefrnhadruu | HO OH | Leia 2006, 4?, 3?07] U " (3) Cunvert pinith [e a chair ecnfcnnatiun. (3(2) has been identified and | HUI the methcsy greup has been added ta get ynu Staftfid+ OH I (4) Write planar prcjecticn ferruulas fer a chirni diastareumer and an i lelfi' _ uchirui diusrareemer cf pinitel a. ( _ I 6) A chemist in Zflrich has CIJOEH | fe ad that (IE, ZS'J-cispentaein is an effective WNHE | chiral catalyst in certain urganic reactiens [Tetrahedrun Len. 2006,, 47, 3343]. The gress # structure cf cispentacin (lUPAC name 2- arninucyclupentanecarbuxylic acid) is shuwn tc Q'aminfifilfifi'fl- the right. penta he carbexylic acid I (4) Write a stereechernical funnula fur (1R, _—— 25*)ucispentacin that shews its sterccchemistry clearly. cispentacin —_.I [-J-muccctn CH3 I (3) Label all sterecgenic carbcns cf (-)-mucccin with asterisks. One sterecgenic carbcn [CO-1)] has been identified fcr yen. I (2) Directly en the structure cf (-)-mucccin write in a pair cf dr'rrst‘arect‘cpic hydrcgens and label them HE and Eh. I (3) SUppcse the ccufiguraticn at (3(4) were inverted. Speculate an the impact cf this mulecular i- change impact an the properties cf (-)-mucccin and justify ycur answer. synthesis cf a structural analcgue cf dccetase] a ccmpcunti used fer the treatment at breast and cyarian cancer [Org Lett. 2006, 8, 2301]. The structure cf 10-deacetylbaccatin 111 is shcwn tn the right. I (3) Lccate and identify twc scurces cf strain in 10- deacetylbaccatin HI. Be specific. tfl—deacetylbaccatin III I (1) Directly en the structural fcrmula cf lU-deacetylbaccatin III lccate the bicyclc[5 .3. ] ]undecene skeletcn. 5 d. ( K 4) Chemists at Pennsylvania State University have recentlydescribed a synthetic apprcach tc cylindricine E},r a tricyclic marine alkalcid isclated frcm Claus-Etna eyfiudrr'es cff O the ccast cf Tasmania [Tstruhedrsn Left. 2006, 4?, 3815]. The / structure cf cylindricine B is Sl’lfl‘INI] tn the right. \H I (2) Directly en the structure highlight the turn rings that are CsHis I jcined by a spirueyeiic ring juncticn. Cylindrmine B J ' (1) Identify the lccaticn cf the heayl grnup ——-— axial gauche equaturial (circle due) I (1) Describe the structural relaticnship cf the hexyl grcup and H3: eis- truns- E- Z - n (3) BONUS QUESTIGN! Wculd jucu identify the nitrugen cf cylindricine B as a sterecgenic atcm? Why cr why net? 4. (l4 Paints) MULTIPLE CHOICE. Write the letter cf the must ccrrect respcnse in the space presided tn the left cf the questicn. Chemists in Taiwan have recently develcped a synthetic rcute tn the twc terpencid natural prcducts tn the right [Org Lea. 2006, 8, 2217]. What term best describes the structural cr sterecchemical relaticnship between them? A. Structural (ccnstituticnal) iscmers B. Ccnfcrmatiunal iscmers t“ Enanticmers D. Diasterecmers An enanticselective synthesis cf (»)-quinic acid, a natural prcduct that has a regulating rule in the bicsynthesis cf arcmatic ccmpcunds, has been develcped by Canadian chemists [Org Lett. 2006, 8, 2035]. The structure cf (-)-quinic acid is shcwn tn the right. Determine the tctal number cf sqauturiue’ substituents in the mere stable chair ccnfcrmaticn cf (-)-quinic acid. A. Twc 13. Three C. Fcur D. Five H-quinic acid 6 Estimate the energy barrier separating the twe intereenvertin g ehair eenfermatiens ef eyelehexane. A. Dkealflmele B. 3 kealfmele C. 11 keah’mele D. 33 kealfmele Which eyelealkane is eerreetly asseeiated with its mast stable eenfennatinn? A. Cyeleprepane: envelepe B. Cyelehutane: pnekered C. Cyelnpentane: fully planar D. Cyelehexane: heat What is the prineipa] senree ef strain in the eenfermatien ef methyleyelnheaane in whieh the methyl green is axial? A. Angie strain E. Tersienal strain C. Bend length strain D. Transarmalar strain The eempeund tn the right was the immediate preeurser te (-)-qninie aeid If... in the synthesis eited en p. a. What term hest deserihes this eempennd? A. Bridged hieyelie eempeund B. Bridged trieyelie eempennd 5 C. eis~fi1sed hieyelie eempeund D. irans—firsed hieyelie eempeund BF Whieh ef the renewing meleenles can exist in mesa fenn’? CH3 Br I . Err A. CHECHECHCHECHg a. K x c. i n. £3ngng.taI<|:Hr.;+r3 Br CH3 CH3 ...
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This note was uploaded on 06/18/2010 for the course CHEM 225 taught by Professor Markdec during the Spring '10 term at University of Michigan-Dearborn.

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Spring 06 Exam 4 Blank - CHEMISTRY 225 TEST #4 JUNE 9, 2006...

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