439085-05-9Relevant academic research and scientific papers
Preparation of (R)-(+)-3-phenyl-2,3,5,6,7,8-hexahydro-oxazolo[3,2-a]pyridin-4-ylium bromide: synthesis of (S)-(+)-coniine, (R)-(-)-coniceine and (R)-(+)-anabasine
Castro, Alejandro,Ramirez, Johana,Juarez, Jorge,Teran, Joel L.,Orea, Laura,Galindo, Alberto,Gnecco, Dino
, p. 2699 - 2708 (2008/09/19)
We describe the transformation of (R)-(-)-1-(2'-hydroxy-1'-phenylethyl)piperidin-2-one 1 into (R)-(-)-3-phenyl-2,3,5,6,7,8-hexahydro-oxazolo[3,2-a]pyridin-4-ylium bromide 2 using POBr3. Reduction of 2 with Red-Al at -78 °C gave (3R,8aR)-(-)-3-phenylhexahydro-2H-oxazolo[3,8-a]-pyridine 3 as a single diastereoisomer. The synthetic potential of these transformation is illustrated by the enantiopure synthesis of (S)-(+)-coniine, (R)-(-)-coniceine and (R)-(+)-anabasine.
Dynamic kinetic resolution and desymmetrization processes: A straightforward methodology for the enantioselective synthesis of piperidines
Amat, Mercedes,Bassas, Oriol,Llor, Nuria,Canto, Margalida,Perez, Maria,Molins, Elies,Bosch, Joan
, p. 7872 - 7881 (2007/10/03)
A straightforward procedure for the synthesis of enantiopure polysubstituted piperidines is reported. It involves the direct generation of chiral non-racemic oxazolo[3,2-a]piperidone lactams that already incorporate carbon substituents on the heterocyclic ring and the subsequent removal of the chiral auxiliary. The key step is a cyclocondensation reaction of (R)-phenylglycinol or other amino alcohols with racemic or prochiral δ-oxo (di)acid derivatives in highly stereoselective processes involving dynamic kinetic resolution and/or desymmetrization of diastereotopic or enantiotopic ester groups.
Enantioselective synthesis of 2-arylpiperidines from chiral lactams. A concise synthesis of (-)-anabasine
Amat, Mercedes,Canto, Margalida,Llor, Nuria,Bosch, Joan
, p. 526 - 527 (2007/10/03)
Cyclodehydration of achiral or racemic aryl-δ-oxoacids with (R)-phenylglycinol stereoselectively affords chiral non-racemic bicyclic lactams, from which the enantiodivergent synthesis of (R)- and (S)-2-phenylpiperidine, the diastereodivergent synthesis of cis- and trans-3-ethyl-2-phenylpiperidine, and the enantioselective synthesis of the piperidine alkaloid (-)-anabasine is reported.
