Carbon-13 Nuclear Magnetic Resonance in Alkaloid Chemistry

Abstract

C-11, 45.0 44.8 44.2 C-12' 46.5 46.5 46.0 C-13' 46.7 46.5 46.0 55.5 56.4 55.5(a) Recorded for the dihydrochloride of A and the dihydrobromides of B and C in deuterivm oxide;no internal standard reported (b)(c) Ambiguous assignments 3. Pyridine and Piperidine Alkaloids The spin-lattice relaxation times were studied to determine the conformation of nicotine (Q) in solution (17).The H(2')-C(Z')-C(3)-C(2) dihedral angle is approximately zero degrees.The shift assignments for nicotine (a) and nornicotine (a) were reported earlier (18).See Table 3.Table 3.(a) Carbon -