Compounds with bridgehead nitrogen. 51—The NMR spectra and stereochemistry of the 6-ethylindolizidines
作者:Lee Banting、Trevor A. Crabb、Andrew N. Trethewey
DOI:10.1002/mrc.1260250416
日期:1987.4
1H and 13C NMR spectroscopy showed that both isomers of 6‐ethylindolizidine adopt predominantly the trans‐fused conformation in CDCl3 at 298 K. ΔG 298⊖ for the cis‐⇌tram‐fused conformational equilibrium in indolizidine must accordingly be not less than 2.8 kcal mol−1.
1H 和 13C NMR 谱表明,6-乙基吲哚里西啶的两种异构体在 298 K 下主要采用 CDCl3 中的反式融合构象。因此,吲哚里西啶中顺式-⇌反式融合构象平衡的 ΔG 298⊖ 必须不小于 2.8 kcal mol -1。