Synthesis of -apovincamine

Schultz, A. G., Malachowski, W. P., Pan, Y. Asymmetric Total Synthesis of (+)-Apovincamine and a Formal Synthesis of (+)-Vincamine. Demonstration of a Practical "Asymmetric Linkage" between Aromatic Carboxylic Acids and Chiral Acyclic Substrates. J. Org. Chem. 1997, 62, 1223-1229. 

Aza-annulation of 104 with a variety of acrylate reagents has been utilized in the synthesis of indoloquinoiizidine alkaloid skeletons (eq. 25). Aza-annulation of 104 was affected with acrylic acid (91%), acrylic acid/DPPA (95%), acryloyl chloride/DMAP (64, 63%), and methyl acrylate (37, 52%) to generate the pentacyclic eburnane skeleton 105.42 Carbonyl reduction gave Wenkert s enamine (106), which was carried on in the synthesis of ( )-apovincamine (107) and the clinically active synthetic analog ( )-Cavinton (108).42... 

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