Absolute stereochemistry of (-)-camoensine and (-)-camoensidine in Maackia species

Article abstract of DOI:10.1139/v94-033

It was demonstrated that the attack of Grignard reagents such as methyl-, allyl-, and 3,3-dimethoxypropyl magnesium bromides on 11,12-dehydrocytisine occurs on the α-face, to give the corresponding 11α-alkylcytisine. (-)-Camoensine and (-)-camoensidine were synthesized from (-)-cytisine via the Grignard reaction. The absolute stereochemistry of the above alkaloids was confirmed to be 7R, 9R, 11R and 6S, 7R, 9R, 11R, respectively.