SYNTHESIS OF URUSHI LIPID

Research Project

Project/Area Number	62550678
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	高分子合成
Research Institution	MEIJI UNIVERSITY
Principal Investigator	MIYAKOSHI Tetsuo FACULTY OF ENGINEERING, MEIJI UNIVERSITY, 工学部, 助教授 (00062018)
Co-Investigator(Kenkyū-buntansha)	YOSHIHIRO Yoshiro FACULTY OF ENGINEERING, MEIJI UNIVERSITY, 工学部, 教授 (70061710)
Project Period (FY)	1987 – 1988
Project Status	Completed (Fiscal Year 1988)
Budget Amount *help	¥1,900,000 (Direct Cost: ¥1,900,000) Fiscal Year 1988: ¥600,000 (Direct Cost: ¥600,000) Fiscal Year 1987: ¥1,300,000 (Direct Cost: ¥1,300,000)
Keywords	urushiol / veratrole / Witting反応 / Withy反応 / 天然物合成 / 漆ピリド / 3-アルケニルカテコール / 高分子モノマー / 側鎖のコンフォメーション / 二重結合の立体選択的合成 / トリエンの合成
Research Abstract	Synthesis of urushiol was studied on the two process. One is the process which uses furan compound, and another process uses veratrole as starting material, respectively. The former process has no need for the protection of reactive hydroxyl groups of catechol ring, but it has a problem how to build catechol ring. The target of the study on this process is to find better precursor of urusiol. Fran compounds were used as starting materials forsynthsizing the precursor of urushiol. 5-substituted tetrahydrofuran compounds were treated through many steps such as electro-oxidation, hydrogenation and claisen condensation, etc, sequentry. Methyl 2,5-dimethoxyterahydro-2-froylacetate (I) is formed from methyl 2-furoate by these treatments, (I) reacted with alkyl halide in the presence of base catalysis and gave methyl alpha-(2,5-dimethoxytetrahydro-2-froyl)-slpha-alkylacetate(II). (II) is a precursor of urusiol and is converted to urushiol by hydrolysis. It became clear that the selection of solvent and alkyl halide had an influence on the yield of (II). Aprotic solvent and alkyl iodide gave good results. In another process using veratrole, the problems are, first, how to protect the reactive hydroxyl groups and how to retrieve them from protection. And second, how to build carbon skeleton of side alkyl group which has identical configuration with that of natural lipid. The results of the research on these problems indicates that the replacement of methoxy group of veratrole with acetoxy group enables ot aviod the side reactions accompanied with retrieval of hydroxylgroups. And the configuration of side alkyl or alkylene group is required to be coincident with that of natural urushi lipid stereochemically. It is practicable to synthesize carbon skeleton, by using wittig reaction, almost identical with natural lipid.