31060-12-5

Upstream product

• 90-82-4 pseudoephedrine 
• 198906-32-0 (1S,2S)-<(2-Methylammonium-1-phenyl)propyl>-(1'-methylethyl)phosphate 
• 321-98-2 (1S,2R)-(+)-ephedrine 

Downstream Products

• 130854-68-1 (2R,4R,5S)-3,4-Dimethyl-2-(4-methoxyphenoxy)-5-phenyl-1,3,2-oxazaphospholidine 2-oxide 
• 195433-96-6 (E)-2-((2S,4S,5S)-3,4-Dimethyl-2-oxo-5-phenyl-2λ⁵-[1,3,2]oxazaphospholidin-2-yloxy)-pent-3-enenitrile 
• 198906-22-8 (1'R/S,2S,4S,5S)-2-[(1'-Cyano-1'-phenyl)methoxy]-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidin-2-one 
• 198906-24-0 (1'R,2S,4S,5S,4''R,6''S)-2-{[1'-Cyano-(7'',7''-dimethylbicyclo[3.1.1]hept-1''-enyl)-1'-phenyl]ethoxy}-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidin-2-one 
• 198906-23-9 (1'R,2S,4S,5S)-2-[(1'-Cyano-1',4-diphenyl)butoxy]-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidin-2-one 
• 169139-21-3 (1'R,2S,4S,5S)-2-[(1'-Cyano-1',4-diphenyl)ethoxy]-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidin-2-one 

Relevant academic research and scientific papers

Stereoselective umpolung reactions with metalated p-chiral cyanohydrin phosphates-enantioselective synthesis of tertiary cyanohydrins

We present the first cyanohydrin derivative 4 that allows diastereoselective umpolung reactions. In 4 the OH group of the cyanohydrin is linked with a chiral phosphate, which can be removed hydrolytically after asymmetric synthesis. Cyclization of pseudoephedrine 1d with POCl3 gave 2d. This was followed by addition of racemic benzaldehyde cyanohydrin 3 to give the key intermediate 4d. With complete retention of the configuration at phosphorus. Deprotonation of 4d, followed by addition of a wide variety of electrophiles afforded the crystalline products 5 with high diastereomeric excesses (de up to 94%). High asymmetric induction was also achieved for the reaction of 4-Li+ with acyl halides, α-bromoacetates, 2-cycloalkenones, α,β-unsaturated esters, and γ-bromoacetates. Lewis acid assisted hydrolysis proceeded without racemization and gave high yields of ketone cyanohydrins 6. From the ring-opened chiral auxiliary 7, optically pure pseudoephedrine 1 was readily recovered by acid hydrolysis. Optically pure (R) and (S) ketone cyanohydrins are now accessible in a very general strategy, which circumvents the substrate limitations of enzymatic synthesis.

Ein chirales Cyanhydrinphosphat als umgepolte Carbonylverbindung - stereoselektive Synthese von tertiaeren Cyanhydrinen

Stichworte: Asymmetrische Synthesen * Cyanhydrine * Umpolung * Wirkstoffsynthesen

The Stereochemistry of the Aryl Phosphate/Aryl Phosphonate Rearrangement in 1,3,2-Oxazaphospholidine 2-Oxides

On treatment with LDA/THF (aryloxy)phospholidines in the pseudoephedrine/ephedrine series undergo P-O to P-C rearrangement to afford arylphospholidines with retention of configuration at phosphorus.The stereochemistry of each product was assigned by 1H NM