Budget Amount *help |
¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2013: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2011: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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Research Abstract |
Toward the total synthesis of antitumor saponins scillascillosides, the stereoselective construction of CDE ring system of these molecules have been explored. Ireland-Claisen rearrangement of the dihydrofurancarboxylate, obtained by intramolecular O-H insertion followed by olefination, proceeded stereoselectively to give the desired stereoisomer in good yield. The product was successfully converted to the CDE ring fragment through an intramolecular 1,3-dipolar cycloaddition and introduction of an angular methyl group. With regard to the key Ireland-Claisen rearrangement, we found that the substitution pattern of the adjacent carbon atom played a pivotal role in directing the stereochemical course of the reaction, and this finding led to the development of methods for the stereodivergent syntheses of two chiral building blocks.
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