Stereoselective additions to the exocyclic CC bond of some α-alkylidene-(+)-camphor derivatives
作者:Uroš Grošelj、David Bevk、Renata Jakše、Anton Meden、Branko Stanovnik、Jurij Svete
DOI:10.1016/j.tetasy.2006.04.014
日期:2006.4
Stereoselective additions to the exocyclic CC double bond of some (1R,3E,4S)-3-alkylidene-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ones and (1R,4E,5S)-4-alkylidene-1,8,8-trimethyl-2-oxabicyclo[3.2.1]octan-3-ones were studied. All additions took place predominantly from the less hindered endo-face of the methylidene compounds to give the corresponding exo-adducts as the major isomers. Thus, catalytic hydrogenations
一些(1 R,3 E,4 S)-3-亚烷基-1,7,7-三甲基双环[2.2.1]庚-2--2-和(1 R,4 E,研究了5 S)-4-亚烷基-1,8,8-三甲基-2-氧杂双环[3.2.1] octan-3-one。所有添加发生主要来自较少阻碍内的亚甲基化合物的-面,得到相应的外-adducts为主要异构体。因此,催化氢化提供了α-烷基化的(1 R,3 R,4 R)-1,7,7-三甲基双环[2.2.1]庚基-2-酮和(1 R,4 R,5R)-1,8,8-三甲基-2-氧杂双环[3.2.1] octan-3-ones in 28-100%de。同样,2,4,6-三取代的苄腈氧化物的1,3-偶极环加成反应生成相应的螺环加合物,其取代度为66-100%。通过2D NMR技术,NOESY光谱和X射线衍射确定了结构。