Partial synthesis of 11-oxygenated erythrina alkaloids
Abstract
Lead tetra-acetate oxidation of erysovine (7) afforded 11α-acetoxyerysovine (8) whereas the isomer, erysodine (6) afforded a quinone derivative (10), which was subsequently transformed into an 11 β-acetoxyerysodine derivative (15), and the aromatic oxidation products (11a) and (11b).