二茂铁基α—二酮合成的新途径

本文报道根据Corey和Seebach“羰基反应活性逆转”原理合成二茂铁基α-二酮的新途径。用锂化二茂铁基二噻烷与一个酯反应,再经HgCl_2-CdCO_3水解得到标题化合物。共合成16种酰基二茂铁基二噻烷和13种二茂铁基α-二酮化合物。除两种外,其余均为新二茂铁衍生物。所有产物的结构都由元素分析、IR和~1H NMR谱确定。本文讨论了反应中二茂铁衍生物在结构及性质上的特点和产物的IR和~1H NMR谱。

A New Route for the Synthesis of Ferrocenyl a-Diketones

A new route for the synthesis of ferrocenyl a-diketones has been developed. The method consists of reacting formylferrocene with propanedithiol-1, 3 to form ferrocenyl dithiane, which is lithiated with BuLi to yield lithiodithiane of ferrocene, and this intermediate is then treated with esters. The addition products of ferrocenyl dithiane are finally hydrolyzed in the presence of HgCl2-CdCO3 to give the subject prodcuts. All the synthesized ferrocenyl dithiane and a-diketoncs, except Ia and I c, are new compounds with their structures comfirmed by elemental analysis, 1R and 1H NMR. The yields of the synthesis are moderately good. Only in two cases the yields are low, the reasons for which are proposed. It is also distinct from that reported in the previous literatures in two respects : there is no 2 :1 addition product formed in the synthesis, and all the ferrocenyl acyl dithiancs arc very easily hydrolysable with HgCl2-CdCO3. These unexpected results are tentatively explained. A brief discussion for the IR and1H NMR of the products is given.