202401-53-4

Upstream product

• 143601-51-8 2-Propionyl-succinic acid 1-tert-butyl ester 4-ethyl ester 
• 202401-43-2 (3R,4R)-3-Chloro-4-hydroxy-hexanoic acid ethyl ester 
• 202401-37-4 (S)-3-Chloro-4-hydroxy-hexanoic acid ethyl ester 
• 139231-22-4 2-Propionyl-succinic acid 1-tert-butyl ester 4-methyl ester 
• 134443-86-0 3-Chloro-4-oxo-hexanoic acid ethyl ester 
• 134443-87-1 3-Chloro-4-oxo-hexanoic acid methyl ester 
• 124929-03-9 tert-butyl 2-phenylselenopropionate 
• 2407-43-4 (5S)-5-ethylfuran-2(5H)-one 
• 202401-51-2 2-((2S,3R,4R)-2-Ethyl-4-iodo-5-oxo-tetrahydro-furan-3-yl)-2-phenylselanyl-propionic acid tert-butyl ester 

Relevant academic research and scientific papers

Highly Enantioselective Synthesis of Both Enantiomers of γ-Substituted Butenolides by Bakers' Yeast Reduction and Lipase-Catalyzed Hydrolysis. Total Synthesis of (3AS,6aS)-Ethisolide, Whisky Lactone, and (-)-Avenaciolide

Reduction of 3-chloro-4-oxoalkanoates 5 with bakers' yeast gave (4S)-3-chloro-4-hydroxyalkanoates, which were hydrolyzed and dehydrochlorinated to give (γS)-alkylbutenolides with >96% ee. Reduction of 5 with NaBH4 gave syn-3-chloro-4-hydroxyalkanoate 6. Asymmetric hydrolysis of syn-4-chloro-3-hydroxyalkanoate (±)-10 with lipase afforded (3R,4R)-6 and (3S,4S)-10 with high optical purities. Hydrolysis and dehydrochlorination of (3R,4R)-6 gave (γA)-alkylbutenolides with >85% ee. Total syntheses of (3aS,6aS)-ethisolide, whisky lactone, and (-)-avenaciolide from these butenolides are described.