Edward W. Hagaman

Dimeric indoline alkaloids of a new biphenyl type

Abstract A 13 C NMR analysis of lochnericine and the new alkaloids peceyline, peceylanine and pelankine is presented and the structures of the indoline dimers described.

The structure of callichiline

Abstract The bis-indoline alkaloid callichiline and five of its derivatives were investigated by the 13C NMR spectral method and their C shifts assigned. This analysis and biogenetic considerations limited the alkaloid to two structures of which one was shown by a single-crystal X-ray crystallographic analysis of the natural base to be the actual structure of the alkaloid. Callichiline crystallizes in the monoclinic system, space group P21, with a = 8.776(3) A, b = 15.443(5) A, c = 14.145(5) A, β = 90.87(3)°, and Z = 2. Atomic positional and thermal parameters were refined by least-squares calculations to R = 0.052 over 2625 reflections measured by diffractometer.

Carbon-13 nuclear magnetic resonance spectral analysis of semibullvalene and related substances

The 13C n.m.r. spectra of semibullvalene and a number of its annulated derivatives provide valuable information on the direction of the valence tautomeric equilibria in nondegenerate examples.