Biosynthetic studies of secondary plant metabolites with carbon-13 dioxide. Nicotiana alkaloids. 2. New synthesis of nornicotine and nicotine. Quantitative carbon-13 NMR spectroscopic analysis of [2',3',N-CH3-13C3]nicotine
Biosynthetic studies of secondary plant metabolites with carbon-13 dioxide. Nicotiana alkaloids. 2. New synthesis of nornicotine and nicotine. Quantitative carbon-13 NMR spectroscopic analysis of [2',3',N-CH3-13C3]nicotine