Reaction of Tetrahydropyranyl Ethers with Triethylsilyl Trifluoromethanesulfonate–2,4,6-Collidine Combination: Speculation on the Intermediate, Efficient Deprotection, and Application to Efficient Ring-Closing Metathesis as a Tether
作者:Hiromichi Fujioka、Takashi Okitsu、Takuya Ohnaka、Yoshinari Sawama、Ozora Kubo、Kazuhisa Okamoto、Yasuyuki Kita
DOI:10.1002/adsc.200600572
日期:2007.3.5
chemoselective deprotection method of THP ethers. The characteristic feature of the reaction is that the reaction conditions are weakly basic. Then, the reaction can proceed without affecting acid-labile protecting groups. Furthermore, the intermediates from alkenol–THP ether were trapped with other alkenols to give acyclic mixed acetals, which were subjected to efficient ring-closing metathesis by using the
四氢吡喃基(THP)醚与三乙基甲硅烷基三氟甲磺酸盐(TESOTf)–2,4,6-可力丁的反应通过胶体盐中间体进行,以高收率得到了醇和4-三乙基甲硅烷氧基丁醛。中间体的结构由1确定1 H NMR和FAB-MS研究并通过用EtOH捕获。该反应用于THP醚的温和,高效和高度化学选择性的脱保护方法。该反应的特征是反应条件是弱碱性的。然后,可以在不影响酸不稳定的保护基的情况下进行反应。此外,将烯醇-THP醚的中间体与其他烯醇截留,得到无环的混合缩醛,然后以四氢吡喃基单元为系绳,进行有效的闭环复分解。