Institut für Organische Chemie, Johannes Gutenberg‐Universit?t Mainz, Duesbergweg 10–14, 55128 Mainz (Germany), Fax: (+49)?6131‐39‐24786
Abstract:
An animalic note : The first total synthesis of the all‐cis nupharamine 2 , an alkaloid from beaver castoreum, is based on the stereoselective domino Mannich–Michael reaction of N‐galactosylfurylaldimine to give 1 (Piv=pivaloyl), subsequent conjugate cuprate addition, and stereoselective protonation of the enolate. These reactions are all controlled by the carbohydrate. Protonation of the enolate after cleavage of the auxiliary leads to epimer 3 .