一种新的合成路线,以2-取代的萘并[2,3- b ]呋喃-4,9-二dione2-取代萘并[2,3- b ]呋喃-4,9-二酮
摘要:
4,9-二甲氧基萘并[2,3- b ]呋喃9是在91%的收率得到经由萘并[2,3-的还原甲基化b ]呋喃-4,9-二酮2。用丁基锂处理9后,使混合物与N,N-二甲基乙酰胺反应,然后用硝酸铈(IV)二铵氧化,得到2-乙酰基萘[2,3 - b ]呋喃-4,9-二酮1。2- Formylnaphtho [2,3- b ]呋喃-4,9-二酮13和2-三甲基甲硅烷-萘并[2,3- b ]呋喃-4,9-二酮14也从获得9通过类似的方法。的halodesilylations 14容易得到2- iodonaphtho [2,3- b ]呋喃-4,9-二酮16,2-bromonaphtho [2,3- b ]呋喃-4,9-二酮17,和2- chloronaphtho [2- ,3 - b ]呋喃-4,9-二酮18的产率分别为82%,93%和83%。此外,14的氮杂硅烷基化以77%的产率得到2-硝基萘[2,3
Reaction of the parent naphtho[2,3-b]furan-4,9-dione 2 with various electrophilic reagents was difficult, and only nitration of 2 gave small amounts of 2-nitronaphtho[2,3-b]furan-4,9-dione 4. Then 2-acetylnaphtho[2,3-b]furan-4,9-dione 1 was not obtained by the acetylation of 2. On the other hand, compound 1 that is isolated from Tabebuia Cassinoides and has cytotoxic activity, was obtained from 3-lithiofuran
母体萘并[2,3 - b ]呋喃-4,9-二酮2与各种亲电试剂的反应很困难,仅硝化2会产生少量2-硝基萘并[2,3 - b ]呋喃-4, 9-二酮4。然后通过2的乙酰化未得到2-乙酰基萘[2,3- b ]呋喃-4,9-二酮1。另一方面,从5-噻吩呋喃中分离出具有毒活性的化合物1,该化合物1是从3-硫代呋喃中分五个步骤制得的。