Eight alkaloids were isolated from the leaves of Alangium bussyanum, six of which were known, viz. tubulosine, 9-desmethyltubulosine, deoxydesmethyltubulosine, O-methyltubulosine, deoxytubulosine and 9- or 10-desmethylprotoemetinol. The two other alkaloids were new and their structures were established as alangiobussine and alangiobussinine by spectroscopic and chemical methods.
We report an efficient method for the synthesis of C(1)-carboxamide derivatives by adding isocyanides to 3,4-dihydroisoquinoline N-oxides and 3,4-dihydro-β-carboline 2-oxide in the presence of TMSOAc. 3,4-Dihydroisoquinoline-1-carboxylamide derivatives and 9-dihydro-3H-pyrido[3,4-b]indole-1-carboxamide derivatives were obtained in reasonable yields. The method could be used to synthesize alangiobussine
Fifteen macrocycles ranging from 11 to 26 atoms, containing two tryptamine units connected by an acyl chain between the N(b) and N(b') atoms and a (poly)methylene linker (or a bond) between C(2) or C(6'), were prepared by two different procedures. (C) 1999 Elsevier Science Ltd. All rights reserved.