Paquette Leo A, Hong Fang-Tsao
Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 43210, USA.
J Org Chem. 2003 Sep 5;68(18):6905-18. doi: 10.1021/jo0301346.
An intramolecular anionic oxy-Cope rearrangement (44 --> 46) serves as the key step in a synthetic approach to the insect antifeedant dumsin. Initial investigations clarified the manner in which (--)-bornyl acetate may be transformed into the exo-norbornenol 44. Two routes were developed to advance beyond 46. The first involved acetal 51 as a matrix that was expected to allow the elaboration of rings D and E. The second plan deferred oxidation of the cyclopentene ring in 46 to a later stage of molecular construction. The latter experiments formed the basis of a protocol that led to the successful acquisition of keto aldehydes typified by 108 and 114.
分子内阴离子型氧杂-Cope重排反应（44→46）是昆虫拒食剂dumsin合成方法中的关键步骤。初步研究阐明了（-）-乙酸冰片酯转化为外向降冰片烯醇44的方式。开发了两条路线以进一步合成超过46的产物。第一条路线涉及将缩醛51作为母体，预期可用于构建D环和E环。第二条方案将46中环戊烯环的氧化推迟到分子构建的后期阶段。后一组实验形成了一个方案的基础，该方案成功获得了以108和114为代表的酮醛。
