110549-07-0Relevant articles and documents
A practical enantioselective synthesis of massoialactone via hydrolytic kinetic resolution
Gupta, Priti,Naidu, S. Vasudeva,Kumar, Pradeep
, p. 849 - 851 (2004)
An efficient enantioselective synthesis of (R)- and (S)-massoialactone has been achieved. The key steps are the hydrolytic kinetic resolution of a racemic epoxyheptane with (R,R)-(salen)-CoIIIOAc complex and ring-closing metathesis of homoallylic alcohol derived acrylate esters using Grubb's catalyst.
A mononuclear manganese complex of a tetradentate nitrogen ligand - Synthesis, characterizations, and application in the asymmetric epoxidation of olefins
Shen, Duyi,Miao, Chengxia,Wang, Shoufeng,Xia, Chungu,Sun, Wei
, p. 5777 - 5782 (2014)
A new chiral manganese complex (C1) bearing a tetradentate nitrogen ligand containing chiral bipyrrolidine and benzimidazole moieties was prepared. The structure of C1 was confirmed by ESI-MS and crystallography. This manganese complex is an active catalyst for the asymmetric epoxidation of various olefins with excellent conversion (up to 99%) and high enantiomeric excess (up to 96%ee) with hydrogen peroxide as the oxidant in the presence of 2-ethylhexanoic acid or acetic acid. Compared with previous structurally similar manganese complexes with different diamine backbones (C2, cyclohexanediamine; C3, diamine from L-proline), C1 showed improved asymmetric induction, especially for simple olefins such as styrene derivatives and substituted chromene. The possible reasons for the improvement of the ee values are discussed in the text on the basis of the crystal structures of the manganese complexes.
Total synthesis of natural (?)- and unnatural (+)-Melearoride A
Reed, Carson W.,Fulton, Mark G.,Nance, Kellie D.,Lindsley, Craig W.
supporting information, p. 743 - 745 (2019/02/09)
This communication details the first total synthesis of the 13-membered macrolide, (?)-Melearoride A, as well as unnatural (+)-Melearoride A. The synthesis features a concise 13 step synthesis (11 steps longest linear sequence) that offers flexible stereo-control and multiple opportunities for unnatural analog synthesis to delve into antifungal SAR. The route features a cuprate addition, an Evans asymmetric alkylation, and a ring-closing metathesis (RCM) to close the 13-membered macrocyclic core.
Photocatalytic Asymmetric Epoxidation of Terminal Olefins Using Water as an Oxygen Source in the Presence of a Mononuclear Non-Heme Chiral Manganese Complex
Shen, Duyi,Saracini, Claudio,Lee, Yong-Min,Sun, Wei,Fukuzumi, Shunichi,Nam, Wonwoo
supporting information, p. 15857 - 15860 (2016/12/23)
Photocatalytic enantioselective epoxidation of terminal olefins using a mononuclear non-heme chiral manganese catalyst, [(R,R-BQCN)MnII]2+, and water as an oxygen source yields epoxides with relatively high enantioselectivities (e.g., up to 60% enantiomeric excess). A synthetic mononuclear non-heme chiral Mn(IV)-oxo complex, [(R,R-BQCN)MnIV(O)]2+, affords similar enantioselectivities in the epoxidation of terminal olefins under stoichiometric reaction conditions. Mechanistic details of each individual step of the photoinduced catalysis, including formation of the Mn(IV)-oxo intermediate, are discussed on the basis of combined results of laser flash photolysis and other spectroscopic methods.
Synthesis of the C(7)-C(22) Sector of (+)-Acutiphycin via O-directed double free radical alkyne hydrostannation with Ph3SnH/Et3B, double I-Sn exchange, and double stille coupling
Hale, Karl J.,Maczka, Maciej,Kaur, Amarjit,Manaviazar, Soraya,Ostovar, Mehrnoosh,Grabski, Milosz
, p. 1168 - 1171 (2014/03/21)
Herein a new double O-directed free radical hydrostannation reaction is reported on the structurally complex dialkyldiyne 11. Through our use of a conformation-restraining acetal to help prevent stereocenter-compromising 1,5-H-atom abstraction reactions b
Bioproduction of chiral epoxyalkanes using styrene monooxygenase from rhodococcus sp. ST-10 (RhSMO)
Toda, Hiroshi,Imae, Ryouta,Itoh, Nobuya
, p. 3443 - 3450 (2015/02/05)
We describe the enantioselective epoxidation of straight-chain aliphatic alkenes using a biocatalytic system containing styrene monooxygenase from Rhodococcus sp. ST-10 and alcohol dehydrogenase from Leifsonia sp. S749. The biocatalyzed enantiomeric epoxidation of 1-hexene to (S)-1,2-epoxyhexane (44.6 mM) using 2-propanol as the hydrogen donor was achieved under optimized conditions. The biocatalyst had broad substrate specificity for various aliphatic alkenes, including terminal, internal, unfunctionalized, and di- and tri-substituted alkenes. Here, we demonstrate that this biocatalytic system is suitable for the efficient production of enantioenriched (S)-epoxyalkanes.
Synthesis of substituted α,β-unsaturated δ-lactones from vinyl tellurides
Oliveira, Juliana M.,R. Freitas, Juliano C.,Comasseto, Jo?o Valdir,Menezes, Paulo Henrique
, p. 3003 - 3009 (2011/04/27)
A new approach for the synthesis of α,β-unsaturated δ-lactones, a unit present in many natural products with interesting biological activities is described. The approach was based on the use of a vinyl telluride, and it is complementary to the methods usi
Total synthesis of berkelic acid
Snaddon, Thomas N.,Buchgraber, Philipp,Schulthoff, Saskia,Wirtz, Conny,Mynott, Richard,Fuerstner, Alois
supporting information; experimental part, p. 12133 - 12140 (2011/02/25)
A productive total synthesis of both enantiomers of berkelic acid (1) is outlined that takes the structure revision of this bioactive fungal metabolite previously proposed by our group into account. The successful route relies on a fully optimized triple-deprotection/1,4-addition/spiroacetalization cascade reaction sequence, which delivers the tetracyclic core 32 of the target as a single isomer in excellent yield. The required cyclization precursor 31 is assembled from the polysubstituted benzaldehyde derivative 20 and methyl ketone 25 by an aldol condensation, in which the acetyl residue in 20 transforms from a passive protecting group into an active participant. Access to fragment 25 takes advantage of the Collum-Godenschwager variant of the ester enolate Claisen rearrangement, which clearly surpasses the classical Ireland-Claisen procedure in terms of diastereoselectivity. Although it is possible to elaborate 32 into the target without any additional manipulations of protecting groups, a short detour consisting in the conversion of the phenolic -OH into the corresponding TBS-ether is beneficial. It tempers the sensitivity of the compound toward oxidation and hence improves the efficiency and reliability of the final stages. Orthogonal ester groups for the benzoate and the aliphatic carboxylate terminus of the side chain secure an efficient liberation of free berkelic acid in the final step of the route. Queue up: Three deprotection and three bond-forming reactions, all of which are effected just by a trace of HCl, zip an easily attained enone to the polycyclic core of berkelic acid in diastereomerically pure form and essentially quantitative yield. This cascade process paves the way to a concise and effective total synthesis of this alleged metalloproteinase-3 inhibitor and cytotoxic metabolite derived from an extremophilic fungus.
Development of a concise and general enantioselective approach to 255-disubstituted-3-hydroxytetrahydrofurans
Kang, Baldip,Mowat, Jeffrey,Pinter, Thomas,Britton, Robert
supporting information; experimental part, p. 1717 - 1720 (2009/09/06)
Concise syntheses of 2,5-disubstituted-3-hydroxytetrahydrofurans have been developed that provide access to each configurational isomer of this scaffold from a single aldol adduct. Application of these methods to the rapid preparation of (6S,7S,9S,1QS)- a
Synthesis of (-)-berkelic acid
Wu, Xiaoxing,Zhou, Jingye,Snider, Barry B.
supporting information; experimental part, p. 1283 - 1286 (2009/06/30)
An extremophilic challenge: Stereospecific condensation of a fully functionalized ketal aldehyde and a 2,6-dihydroxybenzoic acid is the key step in the synthesis of (-)-berkelic acid confirming Fuerstner's reassignment of the stereochemistry at C18 and C1
