CMDITR Review of Undergraduate Research - Pluto - University of ...

Following the cooling down, the product was
extracted with diethyl ether 3 times. The organic
layer is dried, filtered, and recrystallized.
(Additional yields for the above reaction: ct-1-11
(68%), ct-1-29 (87%), and ct-1-43 (85%)).
C 41 H 44 O 12 is reacted with Lithium
Aluminum Hydride and dissolved in anhydrous
tetrahydrofuran to reduce the ester and yield the
product C 19 H 16 O 3 .
O
It was extremely important to keep these reaction
conditions dry because of the tendency for
lithium aluminum hydride to react vigorously
with trace amounts of water. The
reaction proceeded under nitrogen
overnight at room temperature. After
TLC showed the completion of the
reaction, the mixture was then poured
very slowly onto ice, stirred, and
neutralized with 6M Hydrochloric Acid.
The mixture was then extracted with
300 ml of ether 3 times, dried, filtered, and
recrystallized. (Additional yields for the above
reaction: ct-1-17 (67%), ct-1-41 (87%), and ct-1-
51 (93%)).
C 19 H 16 O 3 was dissolved in 200ml of
ethanol, with 0.5g of palladium/charcoal added
as a catalyst. This mixture is placed on the
hydrogenation apparatus in order to convert the
Benzyl groups to hydrogen’s.
The reaction proceeded overnight and a TLC
showed that the reaction went to completion.
The mixture is then filtered in order to remove
the palladium/charcoal, and the solvent is
removed. Crystals that are formed were
recrystallized by ethyl acetate and a small
amount of methanol. (Additional yields for the
above reaction: ct-1-45 (87%), ct-1-49 (87%),
and ct-1-50 (68%)).
C 19 H 16 O 3 , which was also the starting
material for the previous reaction, was reacted
with carbon tetra bromide and
triphenylphosphine and dissolved in anhydrous
THF to yield C 19 H 15 BrO 2 .
O
O
O
O
OH
O
OH
O
O
LiAlH 4
dry THF
1. CBr 4,
2. PPh 3
Room Temp.
anhydrous THF
H 2,, Pd/C
O
HO
O
OH
Br
O
OH
OH
O
O
Br
O
The time for the reaction was a minimum of 20
minutes, or until TLC showed that reaction was
complete. However, TLC showed two different
spots so mixture was separated using Column
Chromatography (silica gel/methylene chloride.)
After solvent was removed from purified
product, it was rinsed with hexanes and white
crystals immediately formed in the flask. This
solution was filtered and weighed. (Additional
yields for the above reaction: ct-1-55 (62%) and
ct-1-57 (80%)).
C 19 H 15 BrO 2 was reacted with C 7 H 8 O 3 , (a
previous product), along with potassium
carbonate and 18-crown-6 ether and dissolved in
acetone solvent to yield the first generation
dendron molecule.
O
O
O
HO
OH
OH
K 2CO 3,, 18-CROWN-6
refkux for 48h
O
OH
O
O
O
CBr 4, PPh 3
O
O
O
O
O
OH
Generation 1 Dendron
Reaction proceeded for 48 hours under nitrogen
at 65°C. TLC showed a small amount of starting
material remaining in the mixture, so mixture
was separated by Column Chromatography
(silica gel/methylene chloride.) Following the
removal of the solvent, the resulting yellow oil
was recrystallized with 3:1 toluene/hexanes.
(Additional yields for the above reaction: ct-1-63
(90%) and ct-1-67 (81%)).
The following and final reaction consisted of
the Generation 1 dendron synthesized in the
previous reaction reacted with carbon tetra
bromide, and triphenylphosphine to yield the
same dendron with a bromide displacing the
hydroxy group.
However, TLC showed that the product was not
forming. Column Chromatography was
performed in order to recover the starting
material. After starting material was recovered,
H’NMR spectra of the substance showed
similarities to the original generation 1 dendron,
but also had peaks representing that of the
bromide dendron. Therefore, a mass spectrum
will be obtained for the substance in order to
clarify if the desired product was achieved.
O
O
Br
O
O
O
O
CMDITR Review of Undergraduate Research Vol. 1 No. 1 Summer 2004 59