Abstract: ¹³C NMR spectra for the four pairs of new tetrahydro-β-carbolines are reported. Chemical shift assignments have been made for all carbons of the tetrahydro-β-carbolincs by APT, HETCOR & HETCOLOC spectra. The chemical shifts of 5-C & 6 -C can be used for configurational assignments of tetrahydro-β-carbolines, for 5-C & 6-C chemical shifts are easily recongnizable. The downfield one is assigned to 5-C & the upfield one assigned to 6-C. In the spectra of 3a, b & 4a, b, both 3-C & 5-C undergo downfield shifts, compared with the corresponding carbons of la, b & 2a, b. Meanwile, 2 -C & 6-C undergo upfield shifts, presumably owing to slight difference in polarization of the C -N bonding electrons.

Key words: Tetrahydro-β-carboline, ¹³C NMR, Configuration