A synthetic method for the title compounds has been developed for the syntheses of sarubicin A (1) and granaticin (2). Tetralones (5) and anthracenones (16) were transformed into 1-hydroxy-1-(1-hydroxyethyl) derivatives of tetralins and tetrahydroanthracenes (8, 18) by the route shown in Charts 2 and 4. The diols were dehydrated to allyl alcohols (11, 19) by acid treatment or by reacting their 1'-monoacetates with thionyl chloride followed by alkaline hydrolysis, the choice of procedure being dependent on the structure of the aromatic ring. cis-Dihydroxylation of the olefins by catalytic osmylation using trimethylamine N-oxide as an oxidant afforded the 1R, 2R, 1'R-triols (12, 20) with 98% stereoselectivity, except in the cases of 11a and 19b, where the stereoselectivities were 95 and 90%, respectively. Oxidative ring closure of the triols to the corresponding oxabicycles (13, 21) was achieved by reaction with N-bromosuccinimide under controlled conditions. The intermediate 4-bromo compounds (14, 15) could be isolated in the reactions of 12c, d and underwent smooth cyclization with silver perchlorate in tetrahydrofuran.
已开发出一种合成标题化合物的方法,用于合成萨布西平A(1)和石榴青素(2)。通过图表2和4所示的路线,四氢
萘酮(5)和四氢
蒽酮(16)被转化为1-羟基-1-(1-羟基乙基)衍
生物的四氢
萘和四氢
蒽(8,18)。二醇通过酸处理或通过其1'-单
乙酸酯与亚
硫酰氯反应后进行碱性
水解脱
水成
烯丙醇(11,19),选择何种程序取决于芳香环的结构。使用
三甲胺N-氧化物作为氧化剂的催化
臭氧化顺式二羟基化烯烃,除了11a和19b的情况外,立体选择性为98%,分别获得了1R,2R,1'R-三醇(12,20),立体选择性为95%和90%。通过在受控条件下与N-
溴代琥珀
酰亚胺反应,三醇氧化环合成相应的氧杂
双环化合物(13,21)。在12c,d的反应中可以分离出中间体4-
溴化合物(14,15),并与
四氢呋喃中的
高氯酸银平滑环合。