CHEM24
l.
Dr. Spence
Providethe completeIUPAC namefor the following compounds:
3 - e t Q - l - . n t h 7 i- t - J e . J r r f -
L { - h e d l ll-- h r g l e n - 5 - r 1 n L
( / ) tl"tttt-f,methyl-)-noner)-t
1nL
2.
When the compoundbelow is treatedwith one equivalentof BH3, where does it rcact? Explain.
Wherewould one equivalentof O: react? Explain.
/oo
i.
,.n
..
"i^ry
r.01
."
(:*
|
-\/\.,v--
z-
t,l"."71t
1rtH7le'v' r
/o^^{fn
t'nor,
/ N#
o
rl
allc.jnt- i5 lrE> h,s&.rcej
crfkav"t nnoft ?'tb t5o
/r4c,tI elt t-fr'uzt Crch
a
J.
We did not coverthe reactionof a terminal alkynewith Br2,H2O (in classor in text) like we did
for an alkene. What product do you think would form under theseconditions?
.\./
//-
.
0Q
-#t
v
o,df
r
/^",\
ftr
i
\.-
(:
t\/'...t.$'
Ft"
€r?"I
Alkynes do not reactwith MCPBA or carbenes,why?
+,6rrr"'' e 6nul gralv* ftr1l>a,ninyc^
Too d,Gfic,r/l1- ,wrrvrYxfJ {,{}g ertol a clw1$. brmet ,{rt,6
Q,r1 gtr*, n
Alkyne synthesis.Alkynes aretypically preparedfrom alkenes,which are in turn preparedfrom
an alkyl halide. How would you convertthe following alkyl bromide into a terminal alkyne?
How would you convert the terminal alkyne into an internal alkyne?
'il[-r'----u'
\/
1FuFt
f<
v
t Natu'fltfa
Z.nr
\)
CHEM24
6.
Dr. Spence
Reactions. Give the structureof the major organicproduct(s)expectedfrom eachof the
following reactions.If necessary,indicateproductstereochemistry.
/1;<\"H
\"/=o
1. O:
-._.----_>
2. H2O2,HO'
+
+ Cu2_t Lla0
o
o
HgSOa,H2SOa
Hzo
-^
\-/
^.'Z
rrY\
\/
l. H2,Lindlar's cat
2. MCPBA (l eq)
&
$(
NaNH2
CH3CH2CH2BT
3. Br2 (l eq)
a
1. BH3 (l eq)
2. IJLO2,HO'
3. H2,Pd/C,EtOH
Li, NH3
M\'r
o">
b
*.roKK+r.W,n
CHEM24
1
Dr. Spence
Synthesis. Show how you would carry-outa synthesisof the following moleculesfrom the
indicatedstarting material. You may use any other organic or inorganic reagentyou need. Show
your product after each step in the synthesis.
,,-\-'-
,/:\
/r $r-,
{
{
\
1 3 t*lz
,
Lnoilar'SC"t
Z. t(oy{
'
/
-
I r At*9r4q
\Urlc)r r Huu
r
fffl
I t,r', ,
I
l x
V
2 $f,>(lce)
\r'\/\
|
)
)ZVVor'l
5 tl"o.
a'\tr'
+
t-)
-^->--l^.-
6 , Znl("('"),ctlol^
I . Y \ t _/
(
/\AQr
,]^
y;f
,/. kor{
}. /irilfilu
\..
4, /\rT
T
/f.
L;),A/y{,
./
3--',a.
o
tl
Ho/'<
H-.-:-H
lu.'vtt.
I l.
! z. r--./1(
f-{-r.c-4
-/
/t.
/ \
aj
4. drcr,.Naal|
8. Draw the skeletal structure corresponding to each of the following names. Make sure that
stereochemistry is clearly indicated.
a. 2-methyl-3-hexyne
b. (Z)-2-butene
c. 5-methyl-2-heptyne
9. Name the following molecules. Make sure to include E/Z designations as appropriate.
a.
1-hexyne
b.
(E)-2-hexene can also use trans-2-hexene
10. Give the missing products, reactants, or reagents for the following reactions.
a.
H2, Pd/C
b.
Br
1 eq. Br2, CCl4
Br
c.
O
1) O3
2) Zn, H3O+
O
H
H
d.
2 eq. HBr
Br
Br
e.
Cl
HC
CNa
will not get alkylation since
not primary alkyl halide
f.
1) NaNH2
2)
Br
g.
OH
1) Hg(OAc)2, H2O
2) NaBH4
h.
OSO2Ph
CN
CN
SN2
don't worry about this
problem
i.
Br
HBr
Cl
Cl
j.
OH
Cl
OH
k.
1) BH3, THF
2) HOOH, -OH
l.
Na, NH3
O
SN2
don't worry
about this answer, for
now we just form the
alkene!!
m.
O
HgSO4, H2SO4, H2O
11. Give the missing reagent(s), reactant(s), or product(s) for the following reactions. If more
than one product would be formed, provide all expected products, and when possible indicate
which would be the major product. Be sure to indicate the stereochemistry and regiochemistry of
the products as appropriate.
a. Review: bromohydrin formation, -OH goes to more highly substituted side just like in
oxymercuration
OH
Br2, H2O
Br
b. many other strong bases also work here
Br
KOtBu
we use NaOH in class
c.
1) BH3, THF
H
OH
2) HOOH, -OH
d.
2 eq. HBr
Br
Br
e. Trans addition of Br's
Br
1 eq. Br2
Br
f. Trans addition of H and Br -- cation intermediate
Br
1 eq. HBr
H
g. Via enol intermediate
O
HgSO4, H2SO4
H2O
h. Starting material must be internal alkyne, else hydroboration/oxidation would lead to the
aldehyde
O
1) BH3, THF
2) HOOH, NaOH
i. All ordinary π bonds reduce with Pd/C. (Note that π bond in benzene rings are not reduced.)
H2, Pd/C
j. The π bonds of benzene rings and ordinary ketones are not reduced.
H2, Pd/C
O
O
k. Step 1 is deprotonation to form the alkyne anion; Step 2 is an SN2 reaction.
1) CH3Li (or NaNH2)
C
CH
C
2)
C
Br
12. Give the missing reagent(s), reactant(s), or product(s) for the following reactions. For
stereoselective reactions, indicate the relative stereochemistry of the products.
a.
1) BH3, THF
H
2) HOOH, NaOH
O
b.
1) excess O3
O
O
+
2) Zn, HOAc
c.
Li, NH3
H
H
OH
O
+ CO2
d.
O
O
1) excess O3
O
+ CO2
+
H
H 3C
2) Zn, HOAc
OH
e.
HO
Br
NaCCH
O
+ HCCH
Br
f.
Br
NaCCH
+ HCCH
g.
O
1) BH3, THF
2) HOOH, NaOH
H
OH
h.
Lindlar catalyst
(Pd/CaCO3, quinoline)
H2 gas
i.
after 1)
Br
1) Br2
HgSO4
2) KOtBu
H2SO4, H2O
Br
j.
1) NaNH2
C
CH
2) Br
C
C
13. Supply the missing reagents, products, or starting materials for each of the reactions shown
below. Make sure to indicate stereochemistry and regiochemistry when appropriate.
O
a.
OH
Br2, H2O
Br
b.
O
HgSO4, H2O
+
1:1
H2SO4
O
c.
1) O3
H
2) Zn, H3O+
O
O
OH
H2CO +
HCO2H
d. Step 1 also possible with H2, Lindlar.
1) Li, NH3
Br
2) Br2
Br
e.
1) NaNH2
Li, NH3
2)
I
f.
HBr
Br
Br
g.
H2, Pd/C
h.
H2, Lindlar catalyst
14. Provide a synthetic sequence to go from the given starting material to the desired product.
Show all reagents and synthetic (not reaction) intermediates. All these syntheses can be
accomplished in two or three steps.
a.
Br
?
Br
Br
KOtBu
1 eq. Br2
we used NaOH for step 1
b.
?
H
Br
O
HC
CNa
1) O3
2) Zn, H3O+
Na, NH3
c.
?
H
Br
O
HC
1) BHR2
2) H2O2, NaOH
CNa
we used BH3 for step 2
d.
?
Br
Br
H2, Lindlar
1 eq.
Br2
e.
?
OH
CH3SO2Cl, NEt3
don't worry about this
problem
OSO2CH3
f.
?
HC
CH
1) NaNH2
2) CH3I
1) NaNH2
2)
Br
g.
?
Br
OH
1) Hg(OAc)2, H2O
2) NaBH4
NaOtBu
we use NaOH step 1
h.
?
Br2
Br
NaOtBu
Br
we use NaOH step 2
i.
?
Br H
H
Li, NH3
Br
Br2
j.
?
Br
NaC
O
CH
HgSO4, H2SO4, H2O
k.
?
H
Br
O
1) O3
2) Zn, H3O+
NaOtBu
we use NaOH step 1
15. Synthesize the following compounds from acetylene (HCCH) and any primary (1°) alkyl
halide(s) (RCH2X, where X = Cl, Br, or I) you would like to use.
a. Note for all of these: NaNH2 is given as the base, but CH3Li and BuLi are equally good.
1) NaNH2
HC
1) BH3, THF
CH
2)
Br
2) HOOH, -OH
O
H
b.
1) NaNH2
HC
Na, NH3
CH
2)
1) Hg(OAc)2, H2O
2) NaBH4
Br
OH
c.
1) NaNH2
HC
1) NaNH2
H2/ Lindlar
CH
2)
2)
Br
Br
Cl2
Cl
Cl
d.
1) NaNH2
HC
Na, NH3
CH
2)
Br2, H2O
Br
OH
Br
e.
1) NaNH2
HC
1) NaNH2
CH
2)
2)
Br
Li, NH3
Br
f.
1) NaNH2
HC
HgSO4, H2SO4, H2O
CH
2)
O
Br
g.
1) NaNH2
HC
Na, NH3
CH
2)
Br
1) BH3, THF
2) HOOH, -OH
HO
16. Synthesize the following molecules using acetylene and any alkyl halide(s).
a. Note for all of these: NaNH2 is given as the base, but CH3Li and BuLi are equally good.
OH
1) NaNH2
HC
1) Hg(OAc)2,
H2O
H2
CH
2)
Lindlar
Br
OH
2) NaBH4
b.
O
OH
1) NaNH2
HC
O
O3
CH
2)
OH
Br
c.
Can't make this one;
explain why!
O
HC
1) NaNH2
1) NaNH2
HgSO4
2) CH3I
2)
H2SO4
H2O
CH
Br
O
d.
HC
1) NaNH2
1) NaNH2
2)
2)
CH
Br
H2
Br
Lindlar
e.
O
H
1) NaNH2
HC
O
1) BH3, THF
CH
2)
2) H2O2, NaOH
Br
H
17. Compound A (C4H6) absorbs two molar equivalents of H2 gas on catalytic hydrogenation
with palladium on carbon. Upon reaction with H2SO4 and H2O, a ketone is formed. Give the two
possible structures for compound A.
"Compound A (C4H6) absorbs two molar equivalents of H2 gas" means there are two  bonds in
A.
"Upon reaction with H2SO4 and H2O, a ketone is formed." Alkynes hydrate to form ketones!
or
18. Compound B has the molecular formula C4H6O. When treated with H2 and a palladium
catalyst, B absorbs one equivalent of H2. Compound B also has a strong IR peak at 1715 cm-1.
Draw a possible structure for B that is consistent with this information.
Compound has one C-C π bond (absorbs one equivalent of H2) and a carbonyl (IR peak at 1715).
A possible structure is:
O