33673-62-0Relevant articles and documents
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
Manna, Avrajit,Chakraborty, Ipsita,Chatterjee, Sandip,Bhaumik, Tanurima
, (2021/10/12)
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
Henrion,Macé,Vallejos,Roisnel,Carboni,Villalgordo,Carreaux
, p. 1672 - 1678 (2018/03/21)
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.
Enantioselective, Catalytic One-Pot Synthesis of γ-Butyrolactone-Based Fragrances
Kumru, Ceyda,Classen, Thomas,Pietruszka, J?rg
, p. 4931 - 4940 (2018/10/15)
Herein the preparative (1 g scale), stereoselective syntheses of various alkyl-substituted γ-butyrolactone fragrances 1 is described. The α,β-unsaturated γ-keto esters 2 as starting materials were synthesized by a Horner-Wadsworth-Emmons reaction and are further reduced by an ene reductase and alcohol dehydrogenase in a one-pot enzyme cascade to nine desired γ-butyrolactones 1, among them whisky (1 c) and cognac lactone (1 d). The products 1 were obtained in moderate to good yields and very good diastereoselectivities. Furthermore, the position of a nBu-substituent was permutated to study the effect on the enzyme cascade.
Organocatalytic sequential α-aminoxylation and cis-Wittig olefination of aldehydes: Synthesis of enantiopure γ-butenolides
Devalankar, Dattatray A.,Chouthaiwale, Pandurang V.,Sudalai, Arumugam
experimental part, p. 240 - 244 (2012/06/04)
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
Sabitha, Gowravaram,Bhikshapathi,Yadav
, p. 561 - 569 (2007/10/03)
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.
Atom transfer radical cyclization (ATRC) applied to a chemoenzymatic synthesis of Quercus lactones
Felluga, Fulvia,Forzato, Cristina,Ghelfi, Franco,Nitti, Patrizia,Pitacco, Giuliana,Pagnoni, Ugo Maria,Roncaglia, Fabrizio
, p. 527 - 536 (2007/10/03)
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.
Stereoselective synthesis of (+)-nephrosteranic acid, (+)-trans-cognac lactone, and (+)-trans-whisky lactone using a chiral cyclohexadienyl Ti compound
Schleth, Florian,Vogler, Thomas,Harms, Klaus,Studer, Armido
, p. 4171 - 4185 (2007/10/03)
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.
Synthesis of all stereoisomers of cognac lactones via microbial reduction and enzymatic resolution strategies
Benedetti, Fabio,Forzato, Cristina,Nitti, Patrizia,Pitacco, Giuliana,Valentin, Ennio,Vicario, Michela
, p. 505 - 511 (2007/10/03)
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.
Baker's yeast-mediated approach to (-)-cis- and (+)-trans-Aerangis lactones
Brenna, Elisabetta,Negri, Claudia Dei,Fuganti, Claudio,Serra, Stefano
, p. 1871 - 1879 (2007/10/03)
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
Forzato, Cristina,Gandolfi, Raffaella,Molinari, Francesco,Nitti, Patrizia,Pitacco, Giuliana,Valentin, Ennio
, p. 1039 - 1046 (2007/10/03)
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.