V;Y. i\ l-' / Student ID: Recitation day and time:

Transcription

1 V;Y i\ l-' / CHEM 333, Professor Zhang, Spring 20L2 Firs hour exam, Feb 14,2412 Prined Name: Reciaion TA Name: Suden D: Reciaion day and ime: Scores: 1)_ 2)?) 4) 5) CU Honor Code Pledge: On my honor, as a Universiy of Colorado a Boulder Suden, have neiher given nor received unauhorized assisance. This is a closed-book exam. The use of noes, models, calculaors, scrach paper will no be allowed during he exam, Please pu all your answers on he es. Use he backs of he pages for scrach. A Parial Periodic Table fia H 2A 3 Li i 4 Be 3A 4A 5A $A 7A B 6 C 7 N d 0 F 2 {e 0 Ne 11. Na 2 Mg 13 A 14 si 15 p 16 s T7 C1 r8 Ar 35 *r 53 Page ll7

2 1) (20 ps) a) lndicae wheher he following five (5) molecules are aromaic, non-aromaic, or ani-aromaic. Assume all he molecules are planar. (2 ps each). b) For he las wo (2) molecules, also provide he hybridizaion of he aoms indicaed wih an affow (2 ps each). f^* \r' nnn G.r-onn^*i c + 1() Dr {' + n" si r \ cho ",o{. \_/ e,.f'o;m4fr F q<- hybridizaion? l;. N-/. rn.} Jfa;,,^a *,c., > y ) H l,r' -z hybridizaion? ^ nl ('') r;'lr'rr} ru ), \ll b) Cyclopropene (1) and cyclopenadiene (2) differ grealy in heir acidiy. in he following Bronsed acid-base reacions of 1 and 2, he compounds are acing as acids (iz-bul-i as base). Circle he compound ha has he larger Qqo going lef o righ (i.e. he sronger acid). (3 ps) H A 1 /T\ //\l \ \_/r \3'l +n-buli#a+n-buane +n_buli,'"\ +(in+nbuane \ -/ d) Briefly explain your answer o par c) above (3 ps). r:'l ir l-,.pr,," lr'r: ;r:'1-11*,i?i'p":r"'j 'n-i'n^'' 'S'r'ln'.l'''sJ'J"eur $ra,.o-,-i6,'ovvi. 'f, ;' 'ariker rjek'*!'.-i:i r r^ E/:v i '*'L'lE /q5rq *L''i*' ff"o' ';n,^'l^ Page 217

3 2) (20 ps) Give he single major produc of eachof he following reacions, carefully showing sereochemisry if appropriae. f a racemae and label i o'rac" is formed. show onlv one enaniomer,. (4 ps each) a) H2, Lindlar caalys.,,1.,'-\-,,\,'cl b) ll \/ a) AlCl3 b) H2O workup c) -ay + A"' r* - A (hea),{)- {*r.u cr,&* d) i) Provide he major and minor producs expeced from he reacion shown below and indicae which is major and which is minor. (6 ps) ii) s his reacion under kineic or hermodynamic conrol? (2 ps),y HBr(requiv), (,/(,, a"-;\ v'n ^a-.fa \'' yc(j";,-ly F^',rn ' lr"d^cr 'Th;u lea cfio,r is a rjp- l{}rr e ria, u,yrn Page 317

4 3) (20 ps) Propose reagens for accomplishing he following ransformaions. NOTE: more han one sep may be required! Try o make your synhesis efficien (i.e. he desired produc should be he major produc, and generally a shorer synhesis is beer han a longer one). You mus use he saring maerial given; you may use any oher reagens you need. Hsc' Hsc' Br H9, A 'H u^ -!r \ F - >< + ->< d) "3v ' ' H Br H H AB11 1:1 mixure b) u ' rr3v ^.:u rl )?H1lAroz, rlnah.y o d) i'\ \2 CL / Al rl9 l \? l e) H3C----H ll0r Gle*+' Z equiv) Br, Br Page 417

5 4) (18 ps) Provide he producs and mechanisms for he following wo (2) reacions. Show every inermediae wih he proper changes and all he arrows required for each sep of he reacion. (3 ps for produc, 6 ps for mechanism).,r-. (^ ;qllz a) -_4\v1i-on.,,/H Hg(OAc)2, H2SOa Hzo l-./ ll g'o- v nro,a l q{ ^^ irfl r\{ "oao -v,^-r'\ {'o A' \ i{./.\ H- o+rg -r Ae {rda,i u'g/ul^ (Da (fl' 4 / Y {) -> fiaa[c L ; r'' b) \, ''''*'-/ 74 pfn H,- "a r--'\l p, &,,z\ry ---V ' a) Li/NH3 (aq.) b) H2O workup za.r : J \ l/!j. Lr- lv "? i \, L; " ejurua+"4) f nr.., rllnyz ( r' inermediae produc '-/ / 1'nF', HBr -"...-_-- -.; ^.A. /---".* /\/..^.h,,n^ej'"s,'r'", { " f fo0uv ' '\ Br,4. N \\ \ \\ a \ \ \ \\.'HC' i J"uN g;) v.y Hl Page 517

6 5) (22 ps) Propose a synhesis of each of he following hree (3) arges, saring wih benzene andlor any oher organic molecules conaining six (6) carbons or less. You may use any necessary inorganic reagens, Try o make your synhesis efficien (i.e. he desired produc should be he major produc, and generally a shorer synhesis is beer han a longer one). More han one sep may be required. a) x Br i Br #r, Vr \/v, -N*,/,{i{1, "L, b) ( D, also known as 2H, is he isoope of 1H) i4\, lu \/' /Y\ \p,{ +l ' Page 617

7 c) \ / 1i'*fi l'13' lriial' * X-rrgr.')i', \ f-"}r- i i, v"o*1, P*:Y \)l 'A \4 C.L, i, irg,.-{!a f l1. ': -, fuill r, H, Linai*f > ''- -> Page 717 r--- -l Toal poins for his pug