Oxidative spirocyclisation routes towards the sawaranospirolides. Synthesis of ent-sawaranospirolides C and D
作者:Jeremy Robertson、Praful T. Chovatia、Thomas G. Fowler、Jonathan M. Withey、Daniel J. Woollaston
DOI:10.1039/b918091e
日期:——
Two routes are described for the synthesis of the sawaranospirolides, stereoisomeric spirolactone ascorbigenins isolated from Chamaecyparis pisifera. Trapping of the keto enal formed by oxidation of a functionalised 2-(4-hydroxybutyl)furan affords a potential butenolide spiroacetal precursor to sawaranospirolides A and C. Alternatively, epoxidation of protected 3-(dihydropyran-2-yl)-3-arylpropanoic
描述了合成锯木螺螺的两种途径,立体异构体 螺内酯从Chamaecyparis pisifera分离得到的抗坏血酸素。捕获由官能化分子氧化形成的酮烯醛2-(4-羟丁基)呋喃 提供了一种潜在的锯齿螺螺A的丁烯内酯螺缩醛前体和 C。或者,受保护的3-(二氢吡喃-2-基)-3-芳基丙酸的环氧化会导致螺内酯化,生成对-sawaranospirolideC; 相关的酸介导的螺环化作用使他们获得了ent- sawaranospirolideD。