1. Regioselective O-demethylation of two C19-diterpenoid alkaloids.
- Author
-
Liang, Xiao-Xia, Chen, Qiao-Hong, and Wang, Feng-Peng
- Subjects
- *
ALKALOIDS , *CHEMICAL reagents , *CHROMATOGRAPHIC analysis , *MASS spectrometry , *METHYLATION , *MOLECULAR structure , *NUCLEAR magnetic resonance spectroscopy , *PHARMACEUTICAL chemistry , *RESEARCH funding , *SOLVENTS , *SPECTROPHOTOMETRY , *TEMPERATURE , *TERPENES - Abstract
The regioselective demethylations of two C19-diterpenoid alkaloids, 2 and 3, have been achieved with HBr-HOAc, trimethylsilyl iodide, or BBr3. It was observed that HBr-HOAc is an optimal demethylating agent for these two C19-diterpenoid alkaloids because it could provide different O-demethylation products by using different reaction temperature and reaction time. Especially, 1-O-methyl group in 2 and 3, one of the most difficult ones to be demethylated, could be removed by the treatment with HBr-HOAc at an elevated temperature and a prolonged reaction time. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF