The structure of chelerythrine free base was examined. When chelerythrine chloride [lb] was treated with aqueous K2CO} solution, bis[6-(5,6-dihydrochelerythrinyl)] ether[3] was obtained. An excess of aqueous ammonia under the same conditions yielded bis [6-(5,6-dihydrochelerythrinyl)] amine [4], The structures of both derivatives were determined by elemental analysis, ir, ID and 2D nmr, eims, and cims. The formation of an unstable hydroxy adduct 2a (pseudobase) was observed in 'H-nmr experiments only.

This review deals with the fully aromatic quaternary benzo[cJphenanthridine alkaloids in several aspects. Firstly nomenclature principles for numbering fused heterocycles are given. Then the richest botanical sources of quaternary benzo[cJphenanthridines are mentioned as well as isolation, separation and determination methods are presented. The emphasis of this survey is focused on chemical reactivity. The main pharmacological effects of quaternary benzo[cJphenanthridine alkaloids are discussed.

No abstract

Keywords: Cycloaddition / Microwave-assisted synthesis / Solvent-free synthesis / YlidesWe report the microwave-assisted solvent-free synthesis of hexahydrochromeno[4,3-b]pyrroles. Intramolecular 1,3-dipolar cycloadditions proceed under these conditions within 15 min in 80% yields. Moreover, we have observed pro- [a]

No abstract

No abstract

Berberine azide, berberine thiocyanate, and 8-cyano-8H-berberine were prepared from berberine chloride, a quaternary protoberberine alkaloid. The molecular and crystal structures of all compounds are reported and discussed.

No abstract