Carbon-13 Nuclear Magnetic Resonance Studies of Some Lycopodium Alkaloids

Abstract

Chem. 53,1936 (1975).The natural abundance 13C magnetic resonance spectra of some Lycopodium alkaloids have been determined at both 25.15 and 22.63 MHz. By using standard techniques it has been possible to make self-consistent assignments of almost all of the resonances. The results suggest some interesting conclusions regarding the stereochemistry of some of the alkaloids and have been used to confirm the stereochemical assignment at C-12 in sauroxine and to assign the preferred conformation (axial) of the N-methyl group in the obscurines and N-methyllycodine. THOMAS T. NAKASHIMA, PETER P. SINGER, LOIS M. BROWNE et WILLIAM A. AYER. Can. J. Chem. 53,1936Chem. 53, (1975.On a determine, i 25.15 et 22.63 MHz, les spectres de resonance magnetique nucleaire du 13C en abondance naturelle de quelques alkaloides Lycopodium. Utilisant les techniques habituelles, on a pu faire des attributions cohkrentes de pratiquement toutes les resonances. Les resultats obtenus suggkrent quelques conclusions interessantes concernant la stereochimie de quelqu'uns des alkaloides et ces rCsultats ont etC utilisb pour confirmer I'attribution stereochimiqueen C-12 dans la sauroxine et pour attribuer la conformation priviligik (axiale) du groupe N-methyle des obscurines et de la N-methyllycodine.[Traduit par le journal]

13C magnetic resonance spectra of some isoquinoline alkaloids and related model compounds

“…It is known from pmr studies (15) that corydaline is a trcms-quinolizidine and mesocorydaline a cis-quinolizidine, in which the methyl groups are axial and equatorial, respectively, in ring C. The change from a trans to a cis configuration in going from 19 to 20 is evident in the upfield shift of carbons, 5,6, 8, and 13 and is attributed to y-gauche interactions (12,16,17) in the c u compound. On the other hand C-14 moves slightly downfield, a trend also observed in the quinolizidine systems of the Nrl~har and Lycopodium alkaloids (3,4). The methyl group also moves downfield as it changes from an axial to an equatorial position, and a sinlilar shift is observed at C-1.…”

“…In the case of the alkaloids, Wenkert et 01. have made thorough studies in the piperidine and indole series (1). More recently this technique has been applied to the lupin alkaloids (21, the Nuphar alkaloids (3), and the Lycopocliurn alkaloids (4). Despite the variety of ;ing systems found in the isoq&noline series, only a few reports have been published on their 13C spectra.…”

Ten New Lycopodium Alkaloids Having the Lycopodane Skeleton Isolated from Lycopodium serratum THUNB.

“…The crude basic fraction obtained by a conventional procedure from the MeOH extract of the club moss L. serratum collected in Boso Peninsula, Japan, was purified by repeated chromatography over SiO 2 to afford new alkaloids, lycoposerramines-F (1, 0.03% based on the crude base), -G (2, 0.13%), -H (3, 0.29%), -I (4, 0.14%), -J (5, 0.08%), -K (6, 0.05%), -L (7, 0.10%), -M (8, 0.10%), -N (9, 0.03%), and -O (10, 0.06%), along with known alkaloids belonging to the lycopodine group, i.e., lycopodine, 30) lucidioline (11), 31) L.20 (12), 15,32,33) lycodoline, 15,24,30,34) deacetyllycoclavine (15), 35,36) acetyllycoclavine (17), 37) serratidine, 38) and serratezomine C. 15) Compound 1, named lycoposerramine-F, was obtained as colorless prisms (mp Ͼ300°C). High-resolution fast atom bombardment mass spectrometry (HR-FAB-MS) analysis gave m/z 296.1848 (MϩH) ϩ (D Ϫ1.4 mmu) and established the molecular formula as C 16 H 25 NO 4 .…”

Lycopodium alkaloids from Palhinhaea cernua

“…[9][10] In our previous research on this plant, palhinine A, a novel C 16 N-type alkaloid was isolated. 9 We now report the isolation and structural elucidation of two new Lycopodium alkaloids (1-2) along with ten previously identified compounds (Figure 1), namely, lycoflexine N-oxide (3) 8 , lycoflexine (4), 11 lycodine (5), 12 α-obscurine (6), 12 dehydroisofawcettiine (7), 13,14 lycopodine (8), 14 5-acetyllycofoline (9), 15 acetylfawcettiine (10), 16,17 cernuine (11) 18 and lycocernuine (12). 18 …”