| Summary: | 碩士 === 朝陽科技大學 === 應用化學系碩士班 === 94 === Part 1
Since we have other applications of various chain-length of ω-bromoalkyl carboxylic acids, we chose to synthesize these compounds from cyclic ketones of different ring size via the oxidation to ω-hydroxyalkyl carboxylic acids followed by bromine substitution of hydroxyl group.
According to the literature oxidation method used for cyclohexanone, the cyclooctanone failed to afford the desired 8-hydroxyoctanoic acid but to yield 1,8-octanedioic acid instead. Therefore, we decided to examine the oxidation to other ring size of cyclic ketones including 5, 6, 7 and 8 member rings.
The oxidation was conducted in (1) acidic condition consisting of formic acid and hydrogen peroxide and (2) alkaline condition consisting of aqueous sodium hydroxide, hydrogen peroxide and optional addition of methanol, respectively. This investigation included the variables, such as (1) reaction temperature, (2) stoichiometry, and (3) reaction time to determine the effect in product formations and yields.
The details of results will be presented in this report. In general, the oxidation products may comprise hydroxyalkanoic acid and/or its corresponding lactone. However, this reaction mixture can be converted readily into its bromoalkanoic acid in the presence of hydrobromic acid.
Overall, the better results were obtained under the alkaline condition. Particularly, it is effective for transformation cyclooctanone of into its bromoalkanoic acid.
Part 2
Recently, voluminous articles deal with Heck, Suzuki, and Sonogashira coupling in the synthesis of various phenylacetylene compounds are reported in the literatures. These products present many specific applications in the electronics with properties such as electroluminescence, photoluminescence, photorefraction,…etc. Consequently, the syntheses of various phenylacetylene based compounds were extensively discussed.
As a result, we attempted to prepare a series of compounds consisting of phenylacetylene as a repeating unit and various electron donating and withdrawing group at the ends of a chain. The target compounds are presented below. Hopefully, these compounds may provide some unique properties for further applications. Their preparation can be carried out by two approaches: (1) step-wise chain lengthening synthesis and (2) convergent synthesis of two intermediates of roughly equal size.
Based on our findings, the compounds tend to have lower solubility in organic solvent and yield of chemical conversion as the chain lengths increase. When both ends of a compound are capped with electron withdrawing groups, its yield of conversion appears better than those of other combinations.
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