STUDIES ON INDIAN MEDICINAL PLANTS : PART 91 - STRUCTURE AND SYNTHESIS OF ALAMARIDINE. A NOVEL 5-METHYLBENZOPYRIDOQUINOLIZINE ALKALOID FROM ALANGIUM LAMARCKII

Article abstract of DOI:10.1016/S0040-4020(01)85978-0

The structure of alamaridine (1), a novel benzopyridoquinolizine alkaloid, was established by spectral data.However, its stereochemistry could only be determined now by a total synthesis involving the key cyclisation of an 1-methyl-2-pyridylmethyl-3,4-dihydroisoquinolinium salt 19a in presence of pivaloyl chloride and triethylamine.O-Benzyldehydroalamaridine thus formed was reduced by sodium cyanoborohydride and then deprotected to obtain alamaridine (1) and 5-epi-alamaridine (26).Isoalamaridine (27) and its 5-epimer (28) were also synthesised following the same route.