Daphcalycinosidines A and B, new iridoid-alkaloids from Daphniphyllum calycinum

Three new alkaloids, daphcalycinosidines A (1) and B (2) and daphcalycic acid (3) have been isolated from the seeds of Daphniphyllum calycinum. The structures and relative stereochemistries were determined on the basis of spectral studies including 2D NMR, mass spectrometry and chemical transformations. Structures 1 and 2 are characterized by an iridoid glucoside moiety linked to new Daphniphyllum alkaloid moieties.     

Corrigendum to “Large scale synthesis of acetylene dicarboxaldehyde mono and diacetal”: [Tetrahedron Lett. 45 (2004) 1829]

In order to succeed in the acidolysis step of the synthesis (1,1,4,4-tetramethoxybut-2-yne 3b yielding 4-dimethoxybut-2-ynal 2b) it is necessary to use undried commercial 95-97% formic acid.