Selective demethylation of some aconitine-type norditerpenoid alkaloids

Joshi, Balawant S. ; Srivastava, Santosh K. ; Barber, Angela D. ; Desai, Haridutt K. ; William Pelletier, S. (1997) Selective demethylation of some aconitine-type norditerpenoid alkaloids Journal of Natural Products, 60 (5). pp. 439-443. ISSN 0163-3864

Full text not available from this repository.

Official URL: http://pubs.acs.org/doi/abs/10.1021/np9606862

Related URL: http://dx.doi.org/10.1021/np9606862

Abstract

Demethylation of some aconitine-type norditerpenoid alkaloids was carried out with trimethylsilyl iodide and with HBr in glacial AcOH. Aconitine (10), cammaconine (23), delphinine (3), falconerine (18), lappaconitine (22), and talatizamine (24) afforded partially demethylated products. When methoxyl groups are present at the C-16 and C-18 positions, these are demethylated, and the methoxyl group at the C-1 position underwent demethylation in none the alkaloids studied except falconerine (18). With HBr-AcOH, in the case of alkaloids possessing a C-3 hydroxyl group, the methoxymethyl at C-18 formed a tetrahydrofuran, cyclizing at the C-6 position. Detailed NMR spectral studies (1H, 13C, 1H homonuclear COSY, HETCOR, and selective INEPT) carried out on the demethylation products have enabled accurate chemical shift assignments to be made for the demethylated alkaloids.

Item Type:Article
Source:Copyright of this article belongs to American Chemical Society.
ID Code:86864
Deposited On:13 Mar 2012 15:03
Last Modified:13 Mar 2012 15:03

Repository Staff Only: item control page