Stereoselective Preparation of Six Diastereomeric Quatercyclopropanes from Bicyclopropylidene and Some Derivatives
作者:Malte von Seebach、Sergei I. Kozhushkov、Heiko Schill、Daniel Frank、Roland Boese、Jordi Benet-Buchholz、Dmitry S. Yufit、Armin de Meijere
DOI:10.1002/chem.200600799
日期:2007.1
Diastereomeric meso- and d,l-bis(bicyclopropylidenyl) (5) were obtained upon oxidation with oxygen of a higher-order cuprate generated from lithiobicyclopropylidene (4) in 50 and 31 % yield, respectively. Their perdeuterated analogues meso-[D(14)]- and d,l-[D(14)]-5 were obtained along the same route from perdeuterated bicyclopropylidene [D(8)]-3 (synthesized in six steps in 7.4 % overall yield from
通过用由硫代二环亚丙基(4)生成的高阶铜酸盐的氧气氧化,分别以50%和31%的收率得到非对映异构的内消旋和d,l-双(双环丙烯基)(5)。他们的全氘化类似物meso- [D(14)]-和d,l- [D(14)]-5是通过相同的路线从全氘化的双环亚丙基[D(8)]-3(按6个步骤以7.4%的合成率)获得的[D(8)]-THF)的总收率各为20.5%。1,1-二溴-2-环丙基环丙烷(6)的脱卤偶合反应以1,69%的产率得到了1,5-二环丙基双环亚丙基16的所有可能的立体异构体的混合物,通过制备型气相色谱从中分离出(Z)-cis-16( 26%的收率)。meso-5的晶体结构看起来像是两个外部双环亚丙基单元(3)和一个内部s-反式-双环丙基单元的晶体结构的叠加,而两个外部环丙基部分相对于(Z)-顺式16的内部双环亚丙基单元上的环丙烷环采用gauche取向。在Meso-5和d,l-5的液氨中用锂桦