SYNTHETIC STUDY ON ANTIFEEDANT OF INSECTS AND RELATED COMPOUNDS

昆虫拒食剂及相关化合物的综合研究

• 批准号: 14560081
• 负责人: WATANABE Hidenori
• 金额: $ 2.11万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14560081/
• 关键词: ANTIFEEDANT; AZADIRACHTIN; SAURIOL; VELAMONE; STEREOSELECTIVE SYNTHESIS; DIELS-ALDER REACTION; RADICAL CYCLIZATION; 昆虫変態阻害; 不斉合成

In the final year, the following researches were carried out.Synthetic study on azadirachtin : Azadirachtin belongs to a class of limonoid which shows antifeeding and growth-inhibitory activities to insects. Although many synthetic chemists have been trying to synthesize the molecule, no total synthesis was reported due to the very complicated structure. This year, we have found that intramolecular Diets-Alder reaction followed by decarboxylation-Claisen rearrangement proceeded efficiently to construct the five asymmetric centers on A-ring. After several steps, a model compound, which possessed a simple cyclopentane ring instead of tricyclic moiety, was prepared and radical cyclization was investigated. The reaction proceeded suite smoothly to form Bring. This approach enables the shorter and more efficient total synthesis than those reported by other groups.Anther compound : In addition to azadirachtin, velamone, which is expected to exhibit the insect antifeedant activity, was synthesized by employing a newly developed intramolecular decarboxylative Robinson annulation which enabled the construction of bicyclic system of the molecule.

印楝素的合成研究：印楝素属于柠檬苦素类化合物，对昆虫具有拒食和生长抑制活性。尽管许多合成化学家一直在尝试合成该分子，但由于其结构非常复杂，还没有全合成的报道。今年，我们发现，分子内Diets-Alder反应，然后脱羧-Claisen重排进行有效地构建五个不对称中心的A-环。经过几步反应，合成了一个模型化合物，它具有一个简单的环戊烷环取代三环部分，并研究了自由基环化反应。反应顺利进行，形成Bring。花药类化合物：除印楝素外，还合成了具有昆虫拒食活性的velamone，该化合物是通过一种新的分子内脱羧罗宾逊环化反应合成的，该反应可以使分子形成双环结构。