131616-48-3

Upstream product

• 157497-25-1 (4R,5R)-5-Butyl-4-hydroxy-4,5-dihydro-2(3H)-furanone 
• 202401-39-6 (S)-3-Chloro-4-hydroxy-octanoic acid ethyl ester 
• 4938-52-7 1-hepten-3-ol 
• 405552-32-1 (1R)-1-[(2'S,3'R)-3-hydroxymethylbicyclo[2.2.1]hept-5-en-2-yl]pentan-1-ol 
• 405552-34-3 (1S)-1-[(2'S,3'R)-3-hydroxymethylbicyclo[2.2.1]hept-5-en-2-yl]pentan-1-ol 
• 628-71-7 1-Heptyne 
• 152442-10-9 (4R,5R)-4,5-dihydro-4-hydroxy-5-iodomethyl-2(3H)-furanone 
• 134443-88-2 3-Chloro-4-oxo-octanoic acid ethyl ester 
• 66696-98-8 tert-butyl ethyl-3-oxopentanoate 
• 528609-53-2 (S)-1-((1S,2R,3S,4R)-3-Hydroxymethyl-bicyclo[2.2.1]hept-5-en-2-yl)-pentan-1-ol 
• 528609-75-8 (1R,2S,5S,6R,7S)-5-Butyl-4-oxa-tricyclo[5.2.1.0^2,6]dec-8-en-3-one 
• 405552-36-5 (2R,5R,6S)-5-butyl-4-oxatricyclo[5.2.1.0^2,6]dec-8-en-3-one 
• 405552-37-6 (2R,5S,6S)-5-butyl-4-oxatricyclo[5.2.1.0^2,6]dec-8-en-3-one 
• 131573-47-2 C₃₃H₃₈O₃ 

Relevant academic research and scientific papers

Catalytic enantioselective synthesis of naturally occurring butenolides via hetero -allylic alkylation and ring closing metathesis

An efficient catalytic asymmetric synthesis of chiral γ-butenolides was developed based on the hetero-allylic asymmetric alkylation (h-AAA) in combination with ring closing metathesis (RCM). The synthetic potential of the h-AAA-RCM protocol was illustrated with the facile synthesis of (-)-whiskey lactone, (-)-cognac lactone, (-)-nephrosteranic acid, and (-)-roccellaric acid.(Figure Presented)

Enantioselective redox-neutral Rh-catalyzed coupling of terminal alkynes with carboxylic acids toward branched allylic esters

We report on the first enantioselective variant of the atom-economic and redox-neutral coupling of carboxylic acids with terminal alkynes under rhodium catalysis utilizing the chiral, bidentate (R,R)-Cp-DIOP ligand. This represents the first example of this convenient asymmetric access to valuable branched allylic esters. The utility of this methodology is demonstrated by both a reaction performed on large scale and a short three-step synthesis of two naturally occurring γ-butyrolactones. A stereochemical model explaining the observed absolute configuration of the products based on DFT calculations is given.

Chemoenzymatic synthesis of optically active γ-alkyl-γ-butenolides

rac-Hept-1-en-3-ol 4 was subjected to an enantioselective esterification in the presence of Novozyme 435 and vinyl crotonate as the acyl donor to give (3S)-oct-1-en-3-yl crotonate 7 in >99% ee and (3R)-alcohol 4 in 99% ee. The E-value of this enzymatic reaction was found to be >1000. The (S)-crotonic ester 7 was converted by ring-closing metathesis (RCM) using Grubbs' catalyst to give (S)-oct-2-en-4-olide 1 in 96% yield while keeping the high enantiomeric excess.

Enantiodivergent syntheses of γ-substituted butenolides with tertiary and quaternary asymmetric centers

Continuous nucleophilic addition with several organometallic reagents to tricyclic lactone (-)-1 proceeded diastereoselectively. Newly generated tertiary and quaternary asymmetric centers were controlled by the order in which the nucleophilic reagents were added. Using this methodology, enantiodivergent syntheses of several γ-substituted butenolides with tertiary and quaternary asymmetric centers were established from a single chiral material.

Concise enantiodivergent synthesis of (+)- and (-)-trans-quercus lactones

A concise enantiodivergent total synthesis of (+)- and (-)-quercus lactones from the known tricyclic lactone (+)-1 as a single chiral template was achieved using the diastereoselective nucleophilic addition of organometallic reagents as the key step.

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.

Concise syntheses of natural γ-butyrolactones, (+)-trans-whisky lactone, (+)-trans-cognac lactone, (-)-methylenolactocin, (+)-nephrosteranic acid, and (+)-roccellaric acid using novel chiral butenolide synthons

cis-4-Hydroxy-5-(iodomethyl)-4,5-dihydro-2(3H)-furanones (1 and ent-1) were converted by cross-coupling with several Grignard-derived cuprates followed by benzoylation and base-induced elimination into new chiral butenolides 12, 14, ent-14, 20, and 27. The sequential conjugate addition - quenching of these butenolides under complete stereocontrol provided several polysubstituted γ-butyrolactones including flavor components [(±)-trans-whisky lactone (3) and (+)-trans-cognac lactone (4)], the antitumor antibiotic lactone (-)-methylenolactocin (5), and lichen components [(+)-nephrosteranic acid (7) and (+)-roccellaric acid (8)].

Pure Enantiomers from Retro-Diels-Alder Processes

Diastereoselective and regioselective transformations of cycloadducts to enantiomerically pure cyclopentadienes are reported.Retro-Diels-Alder processes finally give rise to pure enantiomers in high yield.