10.1016/S0040-4020(97)00377-3
The study presents an enantioselective synthetic route to trans-2,6-disubstituted piperidines, focusing on the synthesis of (S)-2-methyl tetrahydropyridine-N-oxide, a key intermediate. This compound is crucial for constructing trans-2,6-disubstituted piperidines via a [3+2] nitrone cycloaddition reaction. The research demonstrates the utility of this method by synthesizing the fire ant venom alkaloid, (+)-solenopsin-A, through a series of steps including nitrone formation, cycloaddition, and reductive cleavage. The methodology is highlighted for its potential application in synthesizing similar piperidine-based alkaloids, with implications for pharmaceuticals, such as treatments for Alzheimer's disease.
10.1021/ol015743j
The study presents a novel and efficient chiral auxiliary-based method for the synthesis of C-glycosylated amino acids. The key step involves a 1,3-dipolar cycloaddition of a chiral glycine equivalent and carbohydrate building blocks, leading to the formation of products with high regio- and diastereoselectivity. The chiral auxiliary, derived from (?)-menthone or (+)-menthone, allows for the synthesis of corresponding diastereomers. The method is designed to meet criteria for an easy and broadly applicable approach to a variety of products with different configurations, as well as orthogonal protecting group strategies. The study also explores the reductive cleavage of the N?O bond using SmI2, which is compatible with the protecting groups on the glycosidic moiety. The approach is demonstrated to be broadly applicable with various aglycosidic building blocks, and it is shown that a chiral glycine equivalent is necessary for the diastereomeric purity of the cycloaddition products. The research was financially supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie.
C
