259107-28-3

Upstream product

• 207223-22-1 (2S,5S,6R)-2-Hydroxy-2-isopropyl-4,5-dimethyl-6-phenyl-morpholin-3-one 
• 207223-32-3 (5S,6R)-2-(2-propylidene)-4,5-dimethyl-6-phenylmorpholine-3-one 
• 55109-47-2 3-methyl-2-oxobutanoyl chloride 
• 299-42-3 ephedrine 
• 696641-89-1 2-((2S,5S,6R)-4,5-Dimethyl-3-oxo-6-phenyl-morpholin-2-yl)-2-methyl-propionic acid ethyl ester 
• 259107-26-1 8R,6R,9S,5,5,9,10-tetramethyl-1,3,7-trioxa-10-aza-spiro[5,5]undecan-11-one 
• 74-88-4 methyl iodide 

Downstream Products

• 79-50-5 (S)-pantolactone 

Relevant academic research and scientific papers

The synthesis of (S)-( + )-pantolactone and its analogues from an ephedrine-derived morpholinone

An efficient general route for the enantioselective synthesis of (S)-(+)-pantolactone and its analogues has been developed from an ephedrine-derived chiral morpholin-3-one. Selective dialkylation of an ephedrine-derived chiral template without epimerization is the key step in this synthesis.

Enantioselective synthesis of (S)-(+)-pantolactone

(equation presented) The Prins reaction of a chiral alkylidene morpholinone derived from (1R,2S)-ephedrine and 3-methyl-2-oxobutanoic acid proceeds with good diastereoselectivity to generate a spiro bis-acetal. Lewis acid mediated diastereoselective reductive cleavage of the spiro acetal and subsequent removal of the ephedrine portion generates a α-hydroxy-γ-methoxy carboxamide which is readily converted to (S)-(+)-pantolactone with high enantiomeric excess.