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Irall Semester 201-s 0rganic (.hetlistry^ I
llecitation I^ trstructtlt'^ (rlarne,^ clay)^ :
lnstnrctiorts
1. Keep the^ exam^ closccl^ Llntil^ yoLr^ at'e^ instrr'tcted to^ begin.
- 'l'Ie^ exant consists of 10 questions. The^ firstthtngyou^ shoulcl do^ is^ mal<e
sure lhatt lto pagcs^ are missitlg.^ lf^ a^ page is^ missit.tg,^ notify^ a^ proctor
imrnecliately
.j. you^ will have 1l-roup^ ancl^ 15 rninules.^ Qr.restions are labeled^ from'e;tsy'[r.)^ tc-r
harci [x*). Budget yottr^ titne^ wisely.
4., Nlal<e sure^ to show^ all^ of^ yoLrr tvorl<,^ and^ this^ should^ fit
rlto the space^ proviclecl.^ lf you^ neecl^ to^ use^ the^ bacl<^ of the p;iper, you mttst^ nral<e nole ol it in the spatcc^ provided for^ creclit.
Goocl l,Lr cl<!
1..-(15 (^) PorntsJ '2.-(20 (^) pointsJ 3.---(12.5 (^) Points) 4.-(1.2.5 pointsJ 5.--[10 points) 6.-(20 pointsl 7.--(10 pointsl
-I[e?.e \l]\rLte ArcuF[Kff '------^ N0{AloRlUr\ (^) f-I 0['IuL r.t}]0N^ lf,L^ |r'[ir-|I0N
(J,,i l't,tcirr,'r,-' 1
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f,di (^) -l 4
1a. Ranl< the foliowing carbocation stability
and brieflJ, explain your^ enswer'. (5 pointsJx
O- O- tl .rd* ,.nOA 3t
from rrosf stable(1) to^ least stable(4)
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o
/4^ I
4 oo
Aa^
6-8. *.r-^ &u<osc-J,P\lbll:h^ ts^I (^) -{]q-bocJion" 4.' mr\Ur,^.r- C-ac boc-{ion'/^ bo(dc4^ on^ -h.r?+rc-oni.r-S.*-{^ i.o n lb. Plovidei.tntot'espedticnalleofthcfollowingcalbonylsfeSter',carbdxyffcacitt,
I<ctone, aldehyde, forntalclehyde). 'l'hen^ ranl<^ tirern^ from^ most^ reqctive (1) to^ lecrst
reactive (4)^ (5^ points)*
@ ^'J**{
r) nFl
eslc-c ko\o^r-^ €o.r.^^t^ o._fA
1c. Predict the relative acidity^ of^ tlte following^ O-H^ containing^ molecttles^ ancl
expiain yoLlr^ answer, using stl'rtctrtt'es were possible^ in^ sLlpport,^ (5^ poilrtsJ*.
YOH
\e.-s\
o^ o
& {^3 \
?oH .- () ,z/
rnos+ acl&^ c-^ a*cidi^ c-
Cho t.-36*-o.t.<-<-)
,Gr efi (--> -,1a_ (^ dsora.r-cr-
\d:"o
++ - -\o \A.
vv )^ 9-'*
t-o
Explunation: (^) e .,.o-: (^) ^d&d ce-so,\a,\cc_ (^) S{-b,f,\
'tttl Ao^^
o
name
stability rank
atoL.\tk -_-.'-.
raYo' ?
oa
r<< I
( -!--, ^
ttt_io-o-.aoa (^) S (^) -... (^) , b{ -- (^) I (^) C"..^- cls o (^) clt1oc-,[2-e e^ oLo..2e o rr{o^ o.tL,=f (^) "oC6.^- \r
the
\
, V
2ci. show a^ mechanism^ for^ the follor'ving reaction^ that^ explatns
diastereoselectivity [5 points)x***
n k-l H', (^) X{cu3 PPh HrcJH -- -'>>^ Hsc' bH. {
I I -,P?L,,
Q
6- t/^ 9o 'orrn'il..,tu, (^) \
nu( t,
''^??-
e (^) H n lrr" 6t^
t *]^ r5i cv
o -^ PP- ,lnl / H-l-", Hri
u'
u (^) .,,.u -'-'+,,
H,U'-l:'^,
- Show the pt'oductIsJ of the iollowing reactions (^) Ii2,5 point.s^ total,2.5^ poinl-s each) **
a.('l
a"?orr LrAtHo^ '^ (oH
-/ .J
followed by water workup
a-,?o H2SO | | +^ NFt2tt^ --' -_-'- - d**
a\aoH ll=.-> 1 NaH -.' 2. CH3Br
o
6
cfrs
Lr'^ .J ,.-..'r-r , o
fion
gg-!!- (^) (1" - -,2 (^) -
.^--11 H2SO ll\z- (^) cH3oH
5, l'tre 1'ollowing^ two^ alkenes^ coulcl^ theoretically^ be^ converted^ into^ all<ynes^ through
a bromilation/ double^ elirnination^ sequence,^ Which^ one do^ you^ believe^ would^ worl<
better/ faster,^ and explain^ yoLlr^ answer^ using^ stntctures^ to explain yoLtl'elllswer.
[10 points]"xx
A. (^) B"*L,^
I r3v^ r\vl^ Ll 13
r^ st- Ll vr 13
lQrt. (^) vt ^rl
-r,-^
. Nr^Nttl lr3v^ v"J z. l\cll\ll 1. Br H3C (^) ---cH 2. NaNH
which one would work^ better? B.^ u.Jo^ r L,lI l3v r\
PaP
;n$
BP)
-/ B L
H (^) b. rl^ ( tor^ , btL,.
u
u B.
-fl)c+k*rrLrrf 0r c't!^ u^ )s
*0,93t1c.n)o --.> vr1....4^ '^1'uto^ [;_]
H ['lt'P^
'6'frc*r;err)s
.L'
u r nH
"3 -^ -rJz /^
B;f cv'
r'><;
9'rr)
@ ."Js^
{" t)n
@ t"^d)^ +o |l^ 'l br
; sJ^ np^ &'^ 'l;^i*-ho^
$r, .Lic-[^ i^ s
6r"n
P" r-^ -li; '.J fo''"
6. Synthesis Questions. Make sure^ to^ drarv^ out^ allof^ your^ reagetrts^ atid
ir.rtermecliates clearly^ and^ legibly.^ [20 points)**'i
a. (5 points) o tl ,'-,, ol lrr \z\roH
.| c;,+ril
r-rll lo
\N
--=.eou
[)-'.ov
b (5 points) OFI .^^ (^) -- -,-^ /\2/ (, ---^ (,J
'4^w"
Jo,
7, One of the rvarys I<nctwn to^ convert^ l<elones^ into^ eslers^ is^ a^ reacttott^ I<nown as:r
Baeyer-Villiger oxidation. 'l'he^ mechanism^ is^ analogous^ to the^ oxidation^ step of^ the
hydroboration/oxidation leaction.^ Show^ a^ mechanistti^ for^ both^ of^ these reactiotls,
r-rsing the specific re;tctions illustrarted below.****
Oxidation step of^ hydroboration/oxidation^ Baeycr-Vill,ger Oxidalion
ooB H"co-81:l13.U
t-n
o t.l
l-l"C- -oH"
.U nna
n lL/--D_..rn/Vl^ r"l . n
[A] Mechanisrn^ for^ tlte
.), (^ rXoor-- Y-c> H-O-.*r--:>
E\
-o tz
IL3J Mechanism^ for
A
"ffifz
f^ n.c j?o a
cHl
the Baeyer'-Villigcr reactiotr^ [5 points].
^9o*
-*:: -'^ '>
o
H
o^P Flv (=) K ,,O c" cu'')
tl
H.,co- -cH,
oxiclation step oia hydroboration/oxidation [5 lroints).
n/ kO -o[Z ,. I^ At-...-Xr-- (^) ilrc- o
-;> ' 'n Acul^ +^
ootz qc"
t rna/l { o,^ $,,o 6Y cn
