中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | 7-hydroxy-2-methyl-8-(2'-methylprop-2'-enyl)-6,11-dihydroanthra<1,2-b>furan-6,11-dione | 165267-50-5 | C21H16O4 | 332.356 |
—— | 7-methoxy-2-methyl-8-(2'-oxopropyl)-6,11-dihydroanthra<1,2-b>furan-6,11-dione | 101417-92-9 | C21H16O5 | 348.355 |
—— | 2-(2'-chloroprop-2'-enyl)-5-(2"-chloroprop-2"-enyloxy)-1-hydroxyanthraquinone | 101417-88-3 | C20H14Cl2O4 | 389.235 |
—— | 2-(2'-chloroprop-2'-enyl)-5-(2''-chloroprop-2''-enyloxy)-1-methoxyanthraquinone | 164937-14-8 | C21H16Cl2O4 | 403.262 |
6-(1'-Formyl)-1,5-dimethoxy-2-(2″-oxopropyl) anthraquinone (1), a key intermediate in Danishefsky's synthesis of vineomycinone B2 methyl ester (5), has been prepared by a new route from anthrarufin (6) via the intermediate 1-methoxy-2-(2′-methylprop-2′-enyl)-5-(2′-methylprop-2′-enyloxy) anthraquinone (20). An alternative synthesis of the diketone (40) has been achieved via Claisen rearrangement of (20) and a subsequent ozonolysis of the resulting bis ( methylpropenyl ) anthraquinone (26). Other routes to (1) from anthrarufin have been developed. In one, compound (1) was formed in yields of 10-16% as an anomalous product from the ozonolysis of (27). Ozonolyses of mixtures of (27), (37) and (44), obtained by isomerization of (27), afforded (1) in yields of 28-43%. Isomerization of the diphenol (25) with palladium(II) chloride bis ( acetonitrile ) in refluxing chloroform proceeds at a faster rate than the isomerization of (27), thereby affording the mono isomerized diphenol (38) in 37% yield. Methylation of (38) affords (37), a known precursor of (1).