5-<i>E</i><i>ndo</i>-<i>T</i><i>rig</i> Radical Cyclizations of Bromomethyldimethylsilyl Diisopropylpropargylic Ethers. A Highly Diastereoselective Access to Functionalized Cyclopentanes
作者:Stéphane Bogen、Mihaela Gulea、Louis Fensterbank、Max Malacria
DOI:10.1021/jo9904260
日期:1999.6.1
An efficient radical sequence involving a 5-exo-dig, a diastereoselective 1,5-H transfer, and a rarely observed in an all-carbon system 5-endo-trig cyclization allows the construction of cyclopentyl derivatives 2 bearing four controlled stereogenic centers from diisopropyl precursors 1. Olefins 3 were also isolated as minor side products. The effect of the acetylenic substituent Y has been investigated
一个有效的自由基序列,涉及5-exo-dig,非对映选择性的1,5-H转移以及在全碳系统中很少观察到的5-endo-trig环化,使得环戊基衍生物2的结构可以由四个受控的立体异构中心组成二异丙基前体1.还分离了烯烃3作为次要副产物。已经研究了炔基取代基Y的作用,并描述了级联的范围和限制。