A series of N-substituted sulfoximidoyl-1,6,8-nonatrienes and 1,7,9-decatrienes were synthesised and subjected to thermal intramolecular Diels-Alder (IMDA) reactions to give diastereomeric mixtures of substituted bicyclo[4.3.0]nonanes and -[4.4.0]decanes. The reactions showed varying selectivities. Endo/exo selectivity was interpreted in terms of a combination of steric factors and the asynchronous
合成了一系列的N-取代的亚磺
酰亚胺基-1,6,8-
壬烯和1,7,9-癸二烯,并进行热分子内Diels-Alder(I
MDA)反应,得到取代的双环[4.3.0]
壬烷的非对映异构体混合物和-[4.4.0]
癸烷。反应显示出不同的选择性。内/外选择性是根据空间因素和环加成反应的异步性质的组合来解释的。通过考虑二烯在构象扩展的
乙烯基亚砜
亚胺二烯亲和体的较少受阻面上的进攻,可以合理化非对面选择性。