Chiral perhydro-1,3-benzoxazines which carry both olefinic and bromo-aromatic substituents undergo stereo- and regio-radical cyclisations mediated by Bu3SnH. Diastereomeric six-membered and seven-membered rings are formed in positional isomers through selective 6-exo and 7-endo attack respectively.
带有烯烃和
溴芳烃取代基的手性全氢-1,3-苯并噁嗪在 Bu3SnH 的介导下发生了立体和区域辐射环化反应。通过选择性的 6-exo 和 7-endo 攻击,分别形成了非对映的六元环和七元环的位置异构体。