114485-30-2

Upstream product

• 24406-16-4 lithium di-n-butylcuprate 
• 94132-74-8 (3S,4S)-3-methyl-5-tosyloxypentan-4-olide 
• 132609-91-7 (3S,4R,5R)-4-Methyl-5-pentyl-3-trimethylsilanyl-dihydro-furan-2-one 
• 917-54-4 methyllithium 
• 91510-97-3 (-)-(R)-5-pentyl-2(5H)-furanone 
• 936324-78-6 (4S,5R)-4-methyl-5-pentyltetrahydro-2-furanol 
• 3391-86-4 (R)-1-octene-3-ol 
• 63000-65-7 <1S,2S,5S>-2-methyl-6,8-dioxabicyclo<3,2,1>octa-4-one 
• 81469-38-7 methyl (3S,4S)-(-)-4,5-epoxy-3-methylpentanoate 
• 146405-85-8 (3S,4S)-3-Methyl-4-phenylsulfanyl-nonanoic acid 
• 74-88-4 methyl iodide 
• 1391853-43-2 (S)-ethyl 3-((S)-1,4-dioxaspiro[4.5]decan-2-yl)butanoate 
• 155720-24-4 4S,5S-5-Mesyloxymethyl-4-methyl-4,5-dihydro-2(3H)-furanon 
• 109-65-9 1-bromo-butane 

Relevant academic research and scientific papers

Atom transfer radical cyclization (ATRC) applied to a chemoenzymatic synthesis of Quercus lactones

The natural fragrances (+)-trans whisky lactone 2 and (+)-trans cognac lactone 4, together with a minor amount of their (-)-cis stereoisomers, were prepared in 50% and 42% overall yield, respectively, starting from racemic 1-hepten-3-ol (±)-5 and 1-octen-3-ol (±)-6. The procedure involved first the enantioconvergent, lipase mediated transformation of the secondary allylic alcohols derived dichloroacetates (±)-7 and (±)-8 into the corresponding homochiral (+)-7 and (+)-8, combined with their cyclization under a transition metal catalyzed atom transfer process.

REACTIONS OF SOME D-RIBONOLACTONE DERIVATIVES WITH ALKYL CUPRATES. SYNTHESIS OF (+)-ELDANOLIDE AND (+)-TRANS-COGNAC LACTONE.

Reactions of some D-ribonolactone derivatives with alkyl cuprates have been investigated in order to obtain molecules with a (4S,5R)-4,5-dialkyldihydro-2(3H)-furanone type constitution.As a direct application, (+)-eldanolide and (+)-trans-cognac lactone have been synthesized.

Synthesis of all stereoisomers of cognac lactones via microbial reduction and enzymatic resolution strategies

Both enantiomers of the diastereomeric cognac lactones have been synthesised using enzyme assisted reactions in the enantiodifferentiating step. This was accomplished by baker's yeast reduction of their precursors 3-methyl-4-oxononanoic acid and ester and by enzymatic hydrolysis of the latter. An inhibition of hydrolases by the products was observed. Trans-(+)-, trans-(-)-, cis-(+)- and cis-(-)-cognac lactones having 99, 88, 88 and 99% e.e., respectively, were thus obtained. Their CD spectra have also been studied.

A general and concise stereodivergent chiral pool approach toward trans-(4S,5R)- and cis-(4R,5R)-5-alkyl-4-methyl-γ-butyrolactones: Syntheses of (+)-trans- and (+)-cis-whisky and cognac lactones from D-(+)-mannitol

A straightforward synthesis of (+)-trans-(4S,5R)- and (+)-cis-(4R,5R)-whisky lactones starting from D-(+)-mannitol has been reported here in fewer number of efficient steps compared to existing literature processes involving D-mannitol as the chiral pool starting material. Chiron approach directly translated chirality of D-mannitol to one of the two chiral centers in these target molecules. Toward this end, stereoisomerically pure trans- and cis-iodomethyl-γ-lactones were formed in the penultimate step. These two acted as versatile advanced common intermediates as they were also converted to the (+)-trans-(4S,5R)- and (+)-cis-(4R,5R)-cognac lactones, respectively. To the best of our knowledge, till date no synthesis of cognac lactones starting from D-mannitol has been reported. All these lactones are identified as the key aroma components of aged alcoholic beverages.

Asymmetric synthesis of: Trans -4,5-disubstituted γ-butyrolactones involving a key allylboration step. First access to (-)-nicotlactone B and (-)-galbacin

An efficient asymmetric synthesis of trans-4,5-disubstituted γ-butyrolactones from aldehydes and enantioenriched γ-carbamate alkenylboronates is reported. The cornerstone of this strategy is the implementation of sequential [3,3]-allyl cyanate rearrangement/allylboration/nucleophilic addition/cyclisation reactions. Diverse γ-butyrolactones such as the flavouring compounds, (+)-trans-whiskey lactone and (+)-trans-cognac lactone, as well as an advanced intermediate towards the first synthesis of natural products, (-)-nicotlactone B and (-)-galbacin, have thus been obtained.

Organocatalytic sequential α-aminoxylation and cis-Wittig olefination of aldehydes: Synthesis of enantiopure γ-butenolides

A short route to enantiopure γ-butenolides (up to 99% ee) has been developed from readily available starting materials. The strategy involves a sequential organocatalytic α-aminoxylation followed by cis-Wittig olefination of aldehydes. The utility of this protocol has been demonstrated in the asymmetric synthesis of trans-(+)-cognac lactone with high enantiomeric purity.

Radical cyclization route to the stereoselective synthesis of ( )-trans-cognac lactone and ( )-trans-aerangis lactone

Stereoselective total synthesis of two chiral lactones, (+)-trans-cognac lactone (1b) and (+)-trans-aerangis lactone (2c), has been achieved from the same intermediate using a radical-based cyclization route. Copyright Taylor & Francis Group, LLC.

Stereoselective synthesis of (+)-nephrosteranic acid, (+)-trans-cognac lactone, and (+)-trans-whisky lactone using a chiral cyclohexadienyl Ti compound

We present the stereoselective transfer of cyclohexadienyl from 3-metalated 1,4-cyclohexadienes to various aldehydes. Lewis-acid-mediated "allylation" of aldehydes by treatment with 3-silylated and 3-stannylated 1,4-cyclohexadienes could not be achieved with high diastereoselectivity. In contrast, cyclohexadienyl titanium compounds reacted with both aliphatic and aromatic aldehydes with good-to-excellent diastereoselectivities. Reaction of a chiral TADDOL-derived (TADDOL, 2,2-dimethyl-α,α,α′,α′-tetraphenyl-1, 3-dioxolandimethanol) cyclohexadienyl Ti derivative with various aldehydes led to the corresponding homoallylic alcohols with excellent diastereo- and enantioselectivities. Lower selectivities were obtained with chiral β-cyclohexadienyldiisopinocampheylborane. The 1,3-cyclohexadienes are very useful building blocks for the preparation of biologically important γ-butyrolactones. Short efficient syntheses of (+)-nephrosteranic acid, (+)-trans-whisky lactone, and (+)-iram-cognac lactone by desymmetrization of 1,4-cyclohexadiene are described.

Baker's yeast-mediated approach to (-)-cis- and (+)-trans-Aerangis lactones

The first enantioselective synthesis of natural (-)-cis-Aerangis lactone (-)-1a and its (+)-trans-diastereoisomer (+)-1b is described. The key steps in the synthesis are: (i) the enantiospecific and 100% diastereoselective baker's yeast reduction of 1,4-keto acid 2, to afford enantiopure trans-cognac lactone (+)-10; (ii) the regioselective PPL-mediated hydrolysis of the primary acetate moiety of diacetate (+)-(3S,4R)-3, obtained from (+)-10. Chain elongation by one carbon atom via cyanide substitution, and inversion of the configuration of C(5) in nitrile derivative (+)-21a are also required to complete the synthetic route to (-)-1a.

Microbial bioreductions of γ- and δ-ketoacids and their esters

A series of yeasts were used in the bioreductions of aliphatic and aromatic γ- and δ-ketoacids and esters to investigate the preparation of enantiomerically pure γ- and δ-lactones through the intermediacy of their corresponding γ- and δ-hydroxyacids and esters. Bioreduction of ethyl 4-oxononanoate 2a with Pichia etchellsii afforded the γ-nonanolide (+)-5a with 99% e.e., while Pichia minuta proved to be the best choice for the bioreduction of ethyl 2-oxocyclohexylacetate 2e, which afforded cis-(-)-5e and trans-(-)-5e with 98 and 99% e.e., respectively. Reduction of 3-(2-oxocyclohexyl)propionic acid 3e with Pichia glucozyma gave predominantly the corresponding δ-lactone trans-(-)-6e with 94% e.e., whose absolute configuration was determined by means of CD spectroscopy.