Synthesis of Functionalized Cyclopentanes, Cyclohexanes and Cycloheptanes by a Silicon-Induced Domino Reaction
作者:Tycho Michel、Andreas Kirschning、Christian Beier、Nico Bräuer、Ernst Schaumann、Gunadi Adiwidjaja
DOI:10.1002/jlac.199619961115
日期:1996.11
1,3-Functionalized cyclopentanes, -hexanes and -heptanes are obtained by addition of lithiated silyldithioacetals 7 to epoxyhomoallyl tosylates 4–6, The reaction involves a cascade of epoxide ring opening, of Brook 1,4-rearrangement and tosylate substitution. The method is particularly suitable for the preparation of cyclopentanes, whereas cyclohexanes and -heptanes are formed in yields only up to
1,3-官能化的环戊烷,-己烷和-庚烷是通过将锂化的甲硅烷基二硫缩醛7加到环氧同烯丙基甲苯磺酸酯4-6中获得的。该反应涉及环氧化物环的级联,布鲁克1,4-重排和甲苯磺酸酯的取代。该方法特别适合于制备环戊烷,而形成环己烷和庚烷的产率仅高达49%。对映体纯的环氧化物的使用提供了光学活性的环戊烷(S)-10b,d,11a以及氧杂环丁烷(S)-14a,b。二硫缩醛官能团的水解导致相应的酮12,环氧化物的环化作用24b给出了一个稠合环戊烷26,其构造是由二硝基苯甲酸盐的X射线结构分析确定27。环氧化物29b的使用提供了带芳基的四氢呋喃30。