“Abnormal” eight-membered ring formation through SN2′ intramolecular Nozaki/Kishi reaction in a synthetic approach to a taxane precursor
作者:Benoît Muller、Jean-Pierre Férézou、Jean-Yves Lallemand、Ange Pancrazi、Joëlle Prunet、Thierry Prangé
DOI:10.1016/s0040-4039(97)10512-3
日期:1998.1
Two different reactions were experimented for the construction of the eight-membered B-ring of taxane skeleton through the formation of the C9C10 bond. A SmI2 promoted radical reaction on seco-alkynyl aldehydes 11cis or 11trans failed. A Nozaki/Kishi reaction carried out on the seco-iodovinyl aldehyde 12trans led, through an unprecedented intramolecular SN2′ reaction, to the “abnormally” cyclised product
实验了两个不同的反应,以通过形成C9C10键来构建紫杉烷骨架的八元B环。SmI 2促进了对癸炔基醛11顺式或11反式的自由基反应。甲野崎/岸反应进行的开环-iodovinyl醛12反式为首,通过分子内的空前的小号Ñ 2'反应,到“异常”环化的产物14,其结构已被证实通过X射线晶体学。