title: Ring A conformation of aconine and pseudaconine in CDCl3.
abstract: On the basis of intensive interpretation of the 1H NMR spectroscopic data, the ring A conformation of aconine (1) was speculated as twist boat in CDCl3, and as chair or twist boat in acetone-d6 and pyridine-d5. The ring A of pseudaconine (2) adopts the chair conformation in CDCl3, acetone-d6, and pyridine-ds. Accordingly, the boat conformation of ring A in these two diterpenoid alkaloids in CDCl3 reported in the literature [1] should be revised. The difference in 13C NMR data for the same compound (1 or 2) in two different solvents (CDCl3, pyridine-d5) can be attributed to solvent effects.
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Deng
authors.forename: Qiao-Hong
authors.initials: QH
authors.lastname: Chen
authors.forename: Feng-Peng
authors.initials: FP
authors.lastname: Wang
mesh_terms: D000157:Aconitine / Q000031:analogs & derivatives* / Q000737:chemistry; D004224:Diterpenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure
chemical_list: D004224:Diterpenes; C416564:pseudaconitine; C047306:aconine; D000157:Aconitine