(±)-2,5,12-Trihydroxy-1,2,3,4-tetrahydronaphthacene-6,11-dione-2-carboxylic acid was found to readily afford the racemic title compound by successive treatments with N,N′-carbonyldiimidazole and methylmagnesium bromide in the presence of trimethylsilyl triflate. The same reaction scheme could also furnish the optically pure title compound from the (R)-carboxylic acid produced by the optical resolution
发现 (±)-2,5,12-Trihydroxy-1,2,3,4-tetrahydronaphthacene-6,11-dione-2-
羧酸通过用 N,N'-连续处理很容易得到外消旋的标题化合物在三甲基甲
硅烷基
三氟甲磺酸酯存在下羰基二
咪唑和
甲基溴化镁。相同的反应方案也可以由光学拆分产生的 (R)-
羧酸提供光学纯的标题化合物。