326477-50-3

Upstream product

• 108-24-7 acetic anhydride 
• 1026855-17-3 2,2,2-Trifluoro-1-((2R,4S)-4-hydroxy-2-phenyl-piperidin-1-yl)-ethanone 
• 326477-47-8 (2R,4S)-(+)-2-Phenylpiperidine-4-ol 
• 267011-73-4 (R)-(+)-6-phenylpiperidine-2,4-dione 
• 326477-43-4 (4R,6R)-(+)-4-Hydroxy-6-phenylpiperidin-2-one 

Downstream Products

• 175671-49-5 (2R,4S) (+)-cis-4-hydroxy-2-pipecolic acid 

Relevant academic research and scientific papers

Asymmetric synthesis of alkaloids using polyfunctionalized chiral building blocks

Enantiopure N-sulfinyl-δ-amino-β-ketoesters and isoquinolones, prepared from sulfinimines (N-sulfinyl imines) are a new class of polyfunctionalized chiral building blocks. These building blocks provide easy access to enantiomerically pure, functionalized piperidines and tetrahydroisoquinolines with a minimum of chemical manipulation and protecting-group chemistry.

Asymmetric synthesis of the four stereoisomers of 4-hydroxypipecolic acid

The asymmetric synthesis of all four stereoisomers of 4-hydroxypipecolic acid (1) from the polyfunctionalized chiral building blocks δ-amino β-keto esters (S(S),R)-(+)-5 or (R(S),S)-(-)-5 is described. Key steps in the synthesis are the stereoselective reductions of b-phenylpiperidine-2,4-dione (6) and N-sulfinyl δ-amino β-keto esters 5 to cis 4-hydroxy 2-piperidinone 7 and syn-δ-amino β-hydroxy ester 9, respectively. The only protecting/deprotecting group chemistry required is related to the oxidation step.