[reaction: see text]. A new class of tandem [4 + 2]/[3 + 2] cycloadditions of nitroalkenes is described in which both pericyclic processes are intramolecular. Two subclasses of intra [4 + 2]/intra [3 + 2] cycloadditions have been explored in which the dipolarophile is tethered at either C(5) or C(6) of the nitronate. For both families of precursors, the cycloadditions occur in good yield and are found
[反应:请参见文字]。描述了一类新的硝基烯烃的串联[4 + 2] / [3 + 2]环加成,其中两个周环过程都是分子内的。已研究了内部[4 + 2] /内部[3 + 2]环加成的两个子类,其中双极性亲子分子系在
亚硝酸盐的C(5)或C(6)上。对于这两个前体家族,环加成均以良好的产率发生,并且被发现具有高度的区域和立体选择性。该方法将线性多烯转化为带有多达六个立体异构中心的官能化多环系统。