Synthesis of bis-2,5-linked tetrahydrofurans via iodoetherification
作者:Margaret A. Brimble、Michael K. Edmonds
DOI:10.1016/0040-4020(95)00572-p
日期:1995.1
Iodoetherification of alcohol 4 and several ether derivatives 12–15 afforded bis-tetrahydrofurans 8 and 9. The ratio of 89 depended on the nature of the ether substituent with 8 being the major product for R=H, SiMe3, and SitBuPh2 whereas 9 was favoured when R=dichlorobenzyl. Attempts to effect ring expansion of 8 afforded ketone 16 wherein hydride migration had occurred. Iodoetherification of trisubstituted
醇4和几种醚衍生物12-15的碘醚化提供了双四氢呋喃8和9。89的比率取决于醚取代基的性质,其中8是R = H,SiMe 3和Si t BuPh 2的主要产物,而当R =二氯苄基时则以9为佳。试图使环8膨胀,得到其中发生了氢化物迁移的酮16。三取代的羟基烯烃17的碘醚化主要提供碘醚21。尝试增加形成的碘醚22的量导致使用三甲基甲硅烷基醚23的11比率为2122。用Ag 2 CO 3在丙酮水溶液中处理碘醚21和22,立体定向进行,分别得到扩环产物27和28。Pyran 28具有与聚醚抗生素salinomycin中存在的立体化学相同的立体化学。