Spelling suggestions: "subject:"seltenes"" "subject:"beltenes""
1 |
Syntheses of novel antitumor 1,4-anthracenediones and functionized cyclododeciptycene based molecular gearsLou, Kaiyan January 1900 (has links)
Doctor of Philosophy / Department of Chemistry / Duy H. Hua / The description of this thesis is divided into three chapters following the
chronological events of my research development.
In chapter one, a series of new 1,4-anthracenediones were synthesized via
functionalizations of the methyl side chain of 6-methyl-1,4-anthracenedione. The new
1,4-anthracenediones were found to exhibit potent cytotoxic activities against human
L1210 leukemic and HL-60 cell lines. A key intermediate, 6-bromomethyl-1,4-
anthracenedione (1.44), was first synthesized through a sequence of reactions including a
double Friedel-Crafts reaction, reductive quinone formation, and selective benzylic
bromination. The bromide (1.44) was further converted to other 1,4-anthracenediones via
hydrolysis, subsequent oxidation, and reductive amination or nucleophilic substitution.
Chapter two deals with a continuous research project aiming at macropolycyclic
cyclodecitycene or [10]beltene derivative using Diels-Alder reaction as the key strategy
for cyclization. A tetraene, (4aR,5R,7S,7aS,11aR,12R,14S,14aR)-5,7,12,14-tetrahydroxy-
2,3,9,10-tetramethylene-1,4,4a,5,6,7,7a,8,11,11a,12,13,14,14a-tetradecahydro-6,13-obenzenopentacene
(2.51), was synthesized by following previous work from this
laboratory. Unfortunately, the Diels-Alder reaction of tetraene 2.51 with triptycene
bisquinone showed predominantly polymerization over intramolecular cyclization. The
use of double activated quinone such as 1,4,5,8-naphthodiquinone (2.64) and 1,2,4,5-
tetraethoxycarbonyl-1,4-benzoquinone (2.70) as dienophiles gave monoadducts 2.67 and
2.71 respectively. However, they both failed to cyclize under high dilution conditions at
elevated temperature, which may be rationalized by chair conformations adopted in six membered
rings causing unfavorable twist for intramolecular cylization. Further study
showed tetraene 2.51 underwent an unexpected furan ring forming reaction.
In chapter three, an unprecedented substituted cyclododeciptycene,
2,4,6,8,10,12,14,16,18,20,22,24-dodecahydro-9,11,21,23-tetramethoxy-(2,14:4,16:6,18:8,
20:10,22:12,24)-hexa(o-benzeno)-[12]cyclacene-1,3,5,7,13,14,17,19-octaone (3.138),
was successfully synthesized based on a successful intramolecular Diels-Alder reaction, which was developed from the above [10]beltene project and previously reported
literature work. A series of all cis-iptycenequinones were synthesized as bisdienophile
building blocks from a sequence of Diels-Alder reactions, separation of individual Diels-
Alder adducts, enolization, and oxidative demethoxylation. It was found that each Diels-
Alder adduct isomer shows distinguish [superscript]1HNMR signals inherent to its structure. The
characteristic [superscript]1HNMR signals allow the identification of the structures of
iptycenequinones derived from the above reactions. A bisdimethoxyanthracene,
6,8,15,17-tetramethoxy-7,16-dihydro-7,16-(o-benzeno)heptacene (3.56), was synthesized
as bisdiene building block, which reacted with cis,cis-heptiptycene tetraquinone (3.23).
The cycloadduct was transformed to cyclododeciptycene 3.138, whose structure was
firmly established by a single-crystal X-ray analysis.
|
Page generated in 0.0301 seconds