Structural parallels between the cardiotonic steroids and the Erythrophleum alkaloids - I. Synthesis of phenanthrenone precursors to novel Erythrophleum alkaloid analogues
作者:Robert W. Baker、John R. Knox、Dan H. Rogers
DOI:10.1016/s0040-4020(01)81949-9
日期:1991.9
(4aR*,10aR*,10aR*)-10-Hydroxy-7-methoxy-3,4,4a,9,10,10a-hexahydrophenanthren-2(1H)-one (3) has been synthesised with the key step involving intramolecular electrophilic alkylation of the aromatic ring, via a Pummerer rearranged intermediate, to complete the B-ring of the phenanthrene nucleus. Phenanthrenones (4) and (5), bearing a 1-methyl or 1-ethyl group in an axial configuration, have also been
(4a R *,10a R *,10a R *)-10-羟基-7-甲氧基-3,4,4a,9,10,10a-六氢菲蒽-2(1 H)-一(3)已合成关键步骤涉及通过Pummerer重排中间体对芳环进行分子内亲电烷基化,以完成菲核的B环。还通过平行途径制备了具有轴向构型的1-甲基或1-乙基的菲蒽酮(4)和(5):在环化反应期间,α-位于1,3的1-烷基对-二氧戊环保护基进行酸催化的差向异构,以得到所需轴向差向异构体的优势。