| Budget Amount *help |
¥28,700,000 (Direct Cost: ¥28,700,000)
Fiscal Year 1986: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1985: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1984: ¥26,100,000 (Direct Cost: ¥26,100,000)
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| Research Abstract |
The excellent utility of glycosyl fluorides in glycosylation reaction (Mukaiyama et al.) led us to develop their efficient preparative methods involving reaction of hexafluoropropene - <NHR_2> with 1-OH sugar derivatives. Lewis acid-catalyzed coupling reactions of the fluorides with an enol trimethylsilyl ether, cyanotrimethylsilane, and allyltrimethylsilane were effectively induced to give the corresponding C -glycosyl compounds. Based on the results obtained by a series of reactions, steresochemistry and mechanism of the reaction were rationalized.
2'-Deoxyribonucleosides were aroylated with high regioselectivity to give their 5'-aroates in a high yield on treatment with an aroyl chloride through dilution - drop-by-drop - addition procedure, The 5'-aroates were efficiently converted into the corresponding 2',3'-dideoxyribonucleosides in a usual manner. The acylation procedure was also useful for ribonucleosides to give their 5'-acylates and/or 2',5'-diacylates depending on the amount of the acyl chlorides, and the latter were derived into 3',5'-diacylates by treating with Wakogel C-300. In a usual manner, they were converted to 3'- and 2'-THP derivatives which have been known as the key-intermediates for the synthesis of oligoribonucleotides, and, thus, we conducted a series of oligoribonucleotide syntheses bearing both 2'-5' and 3'-5 phosphodiester linkages up to an undecamer, It is noteworthy that a novel polymer support approach with a cellulose acetate which is functionalized with 4-(2-hydroxyethylsulfonyl)dihydrocinnamate made up possible to perform coupling reactions of oligonucleotide-fragments efficiently due to its properties in solubility, demonstrating the excellence of both liquid- and solid-phase approaches. In addition, highly regioselective phenylcarbamoylation, methoxymethylation, and triisopropylsilylation of hydroxyl groups of carbohydrates involving nucleosides, and protection of nucleic acid base moieties of ribonucleosides were developed.
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