| Abstract
| - In this paper we describe the stereoselective synthesis of functionalized lactam 7 via twoenantiospecific piperidine-forming techniques and its employment in a general synthetic approachto Nuphar alkaloids. Specifically, the formation of piperidine 18 by formal [3 + 3] cycloadditionand stepwise annelation processes is described; the latter technique was found to be significantlymore efficient than the Pd-catalyzed TMM addition process. Finally, exploitation of the exocyclicalkene installed in the piperidine-forming reaction in the transformation of 18 to (−)-deoxynupharidine ((−)-2), (−)-castoramine ((−)-3), and (−)-nupharolutine ((−)-4) via intermediate lactam7 is delineated.
|
