Acid-catalysed epimerization of indolo[2,3-a]quinolizidines. 1-, 2- and 3-monosubstituted alkyl derivatives
作者:Mauri Lounasmaa、Lars Miikki、Arto Tolvanen
DOI:10.1016/s0040-4020(97)00197-x
日期:1997.4
Acid-catalysed epimerization of 1-, 2- and 3-monosubstituted 1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine alkyl derivatives in refluxing trifluoroacetic acid (TFA) leads to an equilibrium mixture of C-12b diastereomers. The thermodynamically more stable epimer predominates over the kinetically favoured epimer in a ratio of about 85:15 unless the substituent is at C-1, in which case the ratio
回流三氟乙酸(TFA)中的1-,2-和3-单取代的1,2,3,4,6,7,12,12b-八氢吲哚[2,3- a ]喹啉嗪烷基衍生物的酸催化差向异构化导致C-12b非对映异构体的平衡混合物。除非取代基在C-1上,否则热力学上更稳定的差向异构体比动力学上有利的差向异构体的比例大约为85:15,在这种情况下比例为55:45。当在回流的TFA- d中进行差向异构化时,C-12b处的质子被交换。描述了缺失的2-乙基吲哚并[2,3- a ]喹啉二叠氮烷的新的立体选择性合成。