ChemInform Abstract: Stereoselective Syntheses of Chiral Heterocycles and Alkaloids Using Carbohydrate Auxiliaries

Auxiliary-controlled stereoselective enolate protonation: Enantioselective synthesis of cis and trans annulated decahydroquinoline alkaloids

Abstract The diastereoselective synthesis of the octahydroquinoline enone precursor of pumiliotoxin C is achieved via tandem Mannich-Michael reaction on N-galactosyl imines. Conjugate cuprate addition to the bicyclic enone stereoselectively forms the trans annulated 4a- epi -pumiliotoxin C skeleton in the presence of the carbohydrate auxiliary, and the cis annulated pumiliotoxin C skeleton in its absence.

ChemInform Abstract: Auxiliary-Controlled Stereoselective Enolate Protonation: Enantioselective Synthesis of cis and trans Annulated Decahydroquinoline Alkaloids.

Abstract The diastereoselective synthesis of the octahydroquinoline enone precursor of pumiliotoxin C is achieved via tandem Mannich-Michael reaction on N-galactosyl imines. Conjugate cuprate addition to the bicyclic enone stereoselectively forms the trans annulated 4a- epi -pumiliotoxin C skeleton in the presence of the carbohydrate auxiliary, and the cis annulated pumiliotoxin C skeleton in its absence.

Arabinosylamine in Asymmetric Syntheses of Chiral Piperidine Alkaloids.

The stereodifferentiating potential of arabinosyl aldimines was utilized in stereoselective syntheses of 2-substituted dehydropiperidinones and their further transformation to 2,6-cis-substituted piperidinones. The absolute configuration was proven by X-ray analysis and by the synthesis of the enantiomerically pure alkaloid (+)-dihydropinidine. The presented method offers the possibility to synthesize piperidine derivatives enantiomeric to those obtained by the application of the corresponding galactosylamine auxiliary.