A Domino Ring‐Closure Followed by Retro‐Diels–Alder Reaction for the Preparation of Pyrimido[2,1‐
<i>a</i>
]isoindole Enantiomers
作者:Beáta Fekete、Márta Palkó、István Mándity、Matti Haukka、Ferenc Fülöp
DOI:10.1002/ejoc.201600434
日期:2016.7
A simple method was developed to prepare pyrimido[2,1-a]isoindole derivatives by using di-endo- and di-exo-ethyl 3-aminobicyclo[2.2.1]hept-5-ene-2-carboxylate enantiomers as chiral sources. The method is based on a domino ring-closure reaction of norbornene 2-aminohydroxamic acid followed by microwave-induced retro-Diels–Alder reaction. In the case of enantiomeric starting substances, the chirality
以双内-和双-外-乙基3-氨基双环[2.2.1]庚-5-烯-2-羧酸对映异构体为手性来源,开发了一种制备嘧啶并[2,1-a]异吲哚衍生物的简单方法. 该方法基于降冰片烯 2-氨基异羟肟酸的多米诺环闭合反应,然后是微波诱导的逆狄尔斯-阿尔德反应。在对映体起始物质的情况下,手性从降冰片烯衍生物转移到嘧啶并[2,1-a]异吲哚。合成化合物的构型由 1D 和 2D NMR 光谱[基于 2D NOE 交叉峰和 3JH,H 耦合常数] 和 X 射线晶体学确定。