Studies of intramolecular Diels–Alder reactions of nitroalkenes for the stereocontrolled synthesis of trans-decalin ring systems
作者:David R. Williams、J. Cullen Klein、Nicholas S.C. Chow
DOI:10.1016/j.tetlet.2010.11.012
日期:2011.4
Studies of thermal IMDA cyclizations of (1E,7E)-1-nitro-deca-1,7,9-trienes and (1E,3Z,7E)-1-nitro-deca-1,3,7,9-tetraenes have been examined. Reactions of these nitroalkenes proceed via transition states featuring characteristics of asymmetric stretch asynchronicity and result in stereoselective formation of trans-fused decalin products. Substantial rate acceleration is observed for IMDA cyclizations
(1 E ,7 E )-1-nitro-deca-1,7,9-trienes 和 (1 E ,3 Z ,7 E )-1-nitro-deca-1,3,7的热 IMDA 环化研究,9-四烯已被检查。这些硝基烯烃的反应通过具有不对称拉伸异步特征的过渡态进行,并导致立体选择性形成反式融合十氢化萘产物。观察到 IMDA 环化的显着速率加速,以三烯14为例,这是由于束缚链中取代基的空间排斥,这促进了反式融合26 的容易立体控制的形成。