CHEMISTRY 3331: Fundamentals of Orsanic Chemistrv IFinal Exam

H

-\

OH

-\

H

+BrJ

,/o\/ "o-l-to' \.,--o-.-l-\

Prof. Ognjen S. Miljani6

December 7,2011 Last 4 Digits of Student ID Number:

Read all directions very carefully. Write your answer legibly in the designated spaces and think aboutwhat you are doing. Give only one answer for each question. Total number of points is 400.

1. (40 points) This question has several parts. In each, circle only one compound.

Circle the weakest acid:

n - - lrName: t+V\S\IrR( V'SY(pnnt r.

Circle the weakest bond:

Circle the most stable cation:

ffr'tlCircle the only diene:

FINAL SCORE 4c

2. (120 points) For each of the following reactions or series of reactions, draw the structure of the majorproduct(s) in the box. Be sure to clearly indicate stereochemistry where this is pertinent. If you think thatno reaction occufs, write "No Reaction".

Mo

VTA{7ftON

KOH Br2 / light

1,"r.,."o-^.Y

LJI1) mCPBA

2) NaSH

B,'-

rJ

3z

tlmcean

4q- Na / NH3

Hso*

| ,y ""rrn".

l2) H3o+

1."o. tH2o2

q- q.,_H3O* / A

-.48

---fr-Y

f r, "",rn",|

2) H3o.

ia rr?B"

Na2Cr2O7 PB13

oHC=C

H2l Pt

4c

a

foo

2. (60 points) Give detailed mechanisms which explain the two reactions presented below. Show allcharges and intermediates, and use curved arows to indicate the flow of electrons. Do not drawtransition states.

H2SOa

----+

-Hzo

,l\

I

frn,Oe>

#u*l)'

J +@o

f -^-'ll aI eL-rj

arq ,&J

(y

60t-t'

3. (50 points) For each of the foliowing structures, give a complete systematic IUPAC name. Indicatethe stereochemistry where needed.

tvr 3 rylitono- z, - eh\l - 2,S,e -f"iJt uo,'tbghwz

(tlt,zs, sp-)-zl.l/lltouo -s-eflAf I of)l"Wxo',nl

,6\z#r,JlBr

t4- J-bvo*o - 1,4- htyhdie"t

{-vurn-o,-1 1'o c\d'oooI,,re - 3-al

OH,<L lll'\- ",/''-1

SH

5C

(sd-&\,oo - l-pc,,rtun-0 yutr

4. (50 points) For the fwo conversions given below, outline a series of synthetic steps which wouldefficiently accomplish the conversion. You may use any organic compound with two or less carbons,and any inorganic reagent. Give a step-by-step outline and do not give mechanisms.

fn"v

->_j-

c^.'

--+-_+

crllr

ft/a.n

z) n, oo

lt* otr Jon.;

t t)ctl3m_Jq"

I z)Hrf

ort -J[|+

d"

I

I

I

l

I

I

I

/

I

l

I

Yr%vdf

1,,0,

l''*"'<,eo

f ,to5,3u.

Jz) *"r I r)c4ryn,.

I , nrou

-o\r'0f r)0,

I zlay)rs t

ryc

5. (20 points) Draw the structure of 2,3-difluorobutane.

F| "zt-"1- ./ Y.,/ z

I{

Now, consider the C2-C3 bond in 2,3-difluorobutane and draw all three staggered conformations forthis molecule. Circle the least stable conformation

bvfh aw badr brure .$ {rl6le

Jr,rrh,p,-iulwq+&

2O

7 . (40 points) Molecule A has a mass spectrum characterized by dual molecular ion. The two ions are in1:1 ratio and weigh 164 and 166 mass units. The lH NMR spectrum of this compouns shows threepeaks: a singlet at 0.94 (integrates for 9H), a doublet at 1.79 (integrating for 3H), and. a septet at 3.58(integrating for 1H). Its 13C NMR spectrum contains four peaks, at21.5,25.7, 40.0,and 53.0. Treatmentof compound A with potassium /-butoxide produces compound B, which has molecular formula only asingle molecular ion at 84 mass units, and a diagnostic medium-strength IR absorption at 1660 cm i.

Compound B has four peaks in its lH NMR spectrum: a single at 1.20 (integrates for 9H), and thredouble doublets at 5.02, 5.07, and 5.70, which all integrate for 1H each. Its 13C NMR spectrum has fourpeaks, now at 29.5,33.7 , 106.7, and 155.0. Based on this information, draw the structures of compoundsA and B in the provided boxes, and show your reasoning.

K+ (CH3)3CO-

cNsus ELtt-qdl-b*

M* ions at1l4"no roe@iol + 0nc B-o*irq,ry&lsin 1H NMR:

1.79 (d,3

- 0W( Pr-0Mt^(, I\'tl$t

. (15/8),,v,2+\\l.1vr,p \--l

M* ion at 84, lR: 166o rat-l -''4 peaks,nt* *til-

I1.20 (s, eH), 5_.02 (dg!r) ils.07 (dd, 1H),5.70 (dd, 1H)-@r.sintffi C={[zo.s, ze; , 1 06.7, 1 55. o bo ,.0)

I

I

ftfiol^,d +D {syth la"J

I 21.5,25.7,40.0,53.0 .-_(ur.\rc- J^'t, *,tttn.s@

ctt]-@bosrd0yl

tk{ar4l\

9

4o

)v'bn 4,,

3.58 (septet, 1H)

4 peaks in 13C NMR:

8. (10 points) Enols are normally less stable than their coresponding ketones. In the example below, thistrend is inverted. Explain why.

... {l-".,

PY)\?--

ggHoolllilii

Enolmore stable

Hvd !,rcq?,n boC,'ngU- 0

9. (20 points) Assign (S) or (R) designators to all stereocenters in the molecule of glucose shown below:

Ketone

wil4ri,n ft a" wl ;l"Lilie^, if,

30t0

10. (BONUS CREDIT: 20 points) Formulate your own question related to nuclear magnetic resonancespectroscopy and answer it.

Qr |lo* * \ pu:Lr \^^,r[d /0,) z\yh i,r +1Ar ttc-M{(

J(r".firuF4 ,f Z-b,;\ne!

f,: _:_1rL (u,t\'s, np{rror. trno.rr,.J 25 U9 o*l roo (o/

ft^

2oll

8o n d - D iss ociatio n

EnthalpySond-Dissociation

Enthalpy

Bond kJ/mol

."i.ii-1-1 1

159

tJlI r)lt,. l

-qarl)

-1.1 i

1{rli

lq7"]91ILr

Jt5

.j: I

Ir)l-: r,t

.lt{ I

i;{ll:lt{.i.19

Itr5:::.1X I

.+1{r

44X.t.t():ri5:ll_i8l

kcal/mol Bond kJ/mol kcal/mol

i"l X ir*rrd:*rrJ X X br:tdlil tll) 1)

I: I

t't {'lllr lirt.'lilr.il ('1

ll ltrltllt( ) tlil{) ()l l

allfthyl a.:.rd:t ll, l1

t'ili -1.('l I t ('l(-H r '-- ltr{'}lr I

l'll:'- {)ll6lril: 1* pr:rnrlry c*rbcc:('ll!{'ll- - ll('lt r('ll , . [:{'ll i{'ll , {'l{'}l r{'ll. I,rr

( tIi{ ll.. I

('llil'flt- oll{'1i,('lt.{'il. il(,'il 1( il.(..'l i ' -. l.('t I i( t t.,{'t }- {'l('tJ icl-1.('ll. -..-.. 8r( ftr(H,('11,---i('l-:l i{'}{,{.'H, * r)lt

8ond: ts se{cndrry t::rllgn!i('*l 1t.('il-. ll{{'llri.('il l'it ll,j.-{'ll ( l

i('ll r).('ll llri( lltj-("H i

{('}l {).('ll - (}ll

Ssnds ie terlrnry e€rbon5(('lli)t( ll{ ('fl ' 1,1' 1'

{('ll , )r(' -'- ('l1('l-l,Ir('*ltr{('l| 1lr( -

|

{('llr),{'--{)}l

Olher t il trondsf']h('ll. li thcnzviie;('ll, ( ll( H. llr;rrrrlr;rI'H,,-,,Cll.' Il (rirrrlil)it --- | J { itiilnrirlic l

d ' { bond:{'ilI -- ( it1{'lt1{'lj:-('il.,{'t I ,('it.,-..-('t t.,('t I i

i{'llt),('}1",-('Hti('llrj1(' {'}1,

| ( i,.L

| {}6

5i'i

-i{r

.t {r

Ll()l{}l5X

7tllrJ

,5 I

1r) ll"lJriats5l:ltli i

rli I

l,l -+

itl:ill{l()lfi l

.r561{1.+

.l{rll7l

r.)5

I {}65{1

{)X

a.i,i

9ll{l{r7t'()5

:i)rl

s5li7

I'l: i.]

l(l:1I t)(.,

5,1

7i].:{1

,t

..]x

I {)7,1 I

{1ri.iiJi!,lx

lo7ul{rl1

.i.lel

fii{x53l!{il{l

l2

iI'Tl *== -

n= . C) -il: (/) *= f;0 *i? F *g

r'!j ..tl -i: n ol

:xa-l:=r gl *=

:rn =: | (r=

+frr =

i#*i ,'EE -!,- f\l -= l$*g -n :

: \ J p=;;r $1 o5

tg-;:{s -: iw-;

*F)kts

('t

J< r{o

r t- -i.-i ' O:= -

o:-=

_F'l q?' F *i il<*g I g) *!i o *=

' lU a:- {t -i: c

; .L:{: Eh'-

I h'l r;,.a:

-{ u:-

-: I N)=:"1 rr =

. F =i=cr6=-t:: -l {=.-:o) *i iX+i

i' f,F -.= i<*!:(/):+'(c 5=

: i€*l j So;t o *I ;C}x*

. EE =l! -. <=-=

I :U *i. O -i . -{ *3u o *! tE-ii r *i

-- J-:n= Ut E: ; o:i: o -'=

:;g *== F 5='rL

=

ll -11 *=: CI -=

isHi- ..,{. - =f

3 - {i,: -l -.r: i ;U -1.: rrF trJ i f) *:lr O *?

_b.:-:. t- :=:

- O=

J:; -U :-E; *.+ *=

-T*:i. cL -i iEsr

;rr:

-'. r- ji{-=

I D *=. F @:-.L

iF^sr{o -' :c)*jog -i

(.=::. 1- 3 i"f

- N)=ry:

;, I -:'i(n *: i O *+- a coi-r& :

;* f\.1 * :'- .a e:

--^=- q

==.l J *i , O "o=^ 0J -= . F *a:-,F-

o Cm *!F:

_l-.=iF Ii

-0:; Tl *ri 6' ru: ; (r) *=:,. lr! Qr

.r cE *:'{D *g I ffl rt:;

-r : ; {1 *i

;S*g :- (/) *i;'ff -.1 . Fn?.0n *;::.

: 'fl -l:i \J cnl-f

_:,! X *i

r'S*Eio *=-l:-. -l tn E.,(n *3

o (/) *li', m *= i(nd: is*!

:**i \ .*=! F::= - [Fnl: -l -': i**: al.t .^ Irl *:

: lU -r: E Or:--)i X *r.-. O o! - X:ii- * v'a

-l: F =:i -

*=: z--I (D -l i#-i

*!

::

0-(D c)-ff) CD

cD vtA

cn(D

rF*== o -=

.-Fr =:: I o:: $l *i

i t{ *:.

- o=

LJ :. ()-:'-o *=

! T' *ir St *id

a5:l: U r{:;

\,=r:

-,^:: {* i5=t.!

;

-a*g: g'c

lX*E!T *i = Tt ^:: rl lil-J =J=

:Tl*E5 f- 5=

-:U) ^=- - Ki:

=

.>.^i: -l 6i-< =-r=

; rTl *i: (- a=

. f) .^.* e Xl. .{ "'=i6)*3r l.\ al

,b=

, [D ei'F -= I ..| -!

:, {r *=

:Qs5-r'l ==

i (J',{r.q -3=

r fil **= {t} *i:

-? :: r.l- or;ii O *=

.'Tl _I! 3 8- '. ITI *=---=

. 3:;r 6 ::'--

^Z:?'O i5;

.< *:.(f-:

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