The biphenyl 16 (obtained from α-bromopiperonal and the aromatic iodide 14 by a modified Ullmann reaction) was cyclized by intramolecular hydroxyalkylation to the isomeric alcohols 17a and 17b. These were oxidized using Jones' reagent, to afford the enol 18a, together with the tautomeric β-ketolactone Decarboxylation of this mixture using barium hydroxide, followed by Jones' oxidation gave the isomeric
通过分子内羟烷基化将
联苯16(通过改良的Ullmann反应从α-
溴代
戊二醛和芳香族
碘化物14中获得)环化为异构醇17a和17b。使用Jones′试剂将它们氧化,得到烯醇18a,以及使用
氢氧化钡将该混合物的互变异构体β-酮内酯脱羧,然后进行Jones′氧化,得到异构体γ-
酮酸11a和11b。使用Raphael方法将这些化合物转化为(±)-steganone 1,从3,4,5-三
甲氧基苯甲醛开始的总收率约为10%,从
联苯16开始的总收率为20.7%。。