Studies on cycloaddition reactions of 2,2-dimethyl-3,4-dihydro-2H-pyrrole N-oxide and N-(benzylidene)methylamine N-oxide with α,β-unsaturated lactones & esters
作者:S. Baskaran、C. Baskaran、Pradeep J. Nadkarni、Girish K. Trivedi、J. Chandrasekhar
DOI:10.1016/s0040-4020(97)00403-1
日期:1997.5
Intermolecular asymmetric 1,3-dipolar cycloaddition of 2,2-dimethyl-3,4-dihydro-2H- pyrrole N-oxide and N-(benzylidene)methylamine N-oxide with optically active α,β-unsaturated esters 1,2,4 and 7–9 provided the corresponding diastereomers while chiral sugar lactones gave stereoselectively the cycloadducts 17a and 17b (in the case of dipolarophile 3) and 18 in (the case of the dipolarophile 6) with
2,2-二甲基-3,4-二氢-2 H-吡咯N-氧化物和N-(亚苄基)甲胺N-氧化物的分子间不对称1,3-偶极环加成与旋光性α,β-不饱和酯1,2 ,4和7-9提供了相应的非对映异构体,而手性糖内酯通过无环硝酮B立体选择了环加合物17a和17b(对偶极亲和性3而言)和18(对偶极亲和性6而言)。产品的立体化学已经使用高场核磁共振技术建立了技术。这些反应的区域选择性与FMO系数不一致,并基于通过AM1计算获得的电荷分布进行了解释。