| Summary: | 博士 === 國立清華大學 === 化學系 === 93 === Abstract
The dissertation consists of two chapters. The first chapter describes
the aluminum chloride catalyzed aldol condensation of α-iodo ketone
73 with various aliphatic ketones and aromatic aldehydes and then
to synthesize the small-molecule antiangiogenic analogues of curcumin.
According to the difference of substituent on aliphatic or aromatic
ketones, this method could be applied to the synthesis of diversiform
enones, β-hydroxy orβ-chloro ketones. Finally, the synthesis of
Curcumin 62 was completed by using acetylacetone as starting material
reacted with aluminum chloride and vanillin in an one-step procedure.
The second chapter of this dissertation describes the study of the synthesis of Guanacastepene A (1). The starting material dienone 114b
was synthesized from cycloheptanone in four steps. Diels-Alder reaction
of 114b with trans-1,3-pentadiene using aluminum chloride as a catalyst
gave compound 116 with the 7,6-fused ring skeleton. Treatment of 116
with diverse Grignard reagents in the presence of CuI and TMSCl were
then converted to ketones 133 and 136 by produce silylenolethers 131
and 134. Compounds 131 and 134 α-iodination with NaI and m- CPBA
, respectively. Furthermore, reaction of dienone 114b with Grignard
reagent prepared from 4-iodo-1-trimethylsilyl-1-butyne and Mg to
generate silylenolether 142, followed byα-iodination gave the α-iodo
ketone 143. Application of radical cyclization of α-iodo ketone 143
using ditin gave compounds 114a and 114b with the 7,5- fused ring
skeleton. On the other hand, the dienone 114a with β- methyl group
was synthesized in two steps starting from phorone. Reaction of dienone
114a with Grignard reagent prepared from 5-bromo-1-pentene and Mg
gave compound 186. Treatment of 186 with Oxone®, sodium bromide and
triethylamine produce 190. Finally, reaction of 190 with DBU
underwent intramolecular cyclization to construct the 7,6-fused ring
skeleton 191 with two methyl group at C-7 and C-9a successfully.
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