51154-96-2Relevant academic research and scientific papers
Copper(I)-catalyzed enantioselective synthesis of α-chiral linear or carbocyclic (e)-(γ-alkoxyallyl)boronates
Yamamoto, Eiji,Takenouchi, Yuta,Ozaki, Taichi,Miya, Takanori,Ito, Hajime
, p. 16515 - 16521 (2014)
A new method has been developed for the catalytic asymmetric synthesis of α-chiral linear or carbocyclic (γ-alkoxyallyl)boronates via the copper(I)-catalyzed γ-boryl substitution of allyl acetals. This reaction afforded the products in high yields with ex
SECONDARY METABOLITES BY CHEMICAL SCREENING - 13. ENANTIOSELECTIVE SYNTHESIS OF δ-LACTONES FROM STREPTENOL A, A CHIRAL BUILDING BLOCK FROM STREPTOMYCES
Romeyke, Yvonne,Keller, Martin,Kluge, Heinz,Grabley, Susanne,Hammann, Peter
, p. 3335 - 3346 (1991)
The enantioselective synthesis of all four stereoisomers of the secondary metabolite 3-hydroxy-5-decanolide (4a) from Cephalosporium recifei and both enatiomers of massoialactone (5a) by starting from one chiral building block, streptenol A (1a), a secondary metabolite from Streptomyces sp., is described.The key steps of the reaction sequence involve diastereoselective reduction of 1a to syn- or anti-triol 2a and 2b and the regioselective oxidation of the primary hydroxyl group.This reaction furnishes in one step the δ-lactones 3a and 3b and requires no protecting group.
Organocatalytic enantioselective approach to the synthesis of verbalactone and (R)-massoialactone
Harbindu, Anand,Kumar, Pradeep
, p. 1954 - 1959 (2011)
The organocatalytic enantioselective synthesis of verbalactone and (R)-massoialactone is described. The requisite stereogenic centers of the target molecules were constructed using l-proline-catalyzed -aminoxylation and Horner-Wadsworth-Emmons (HWE) olefination. Yamaguchi macrolactonization and ring-closing metathesis were employed as key steps in the syntheses. Georg Thieme Verlag Stuttgart - New York.
One-pot diastereoselective preparation of α,β-unsaturated-γ-silylated-δ-lactones: Application towards natural compounds
Marion,Le Fol,Courillon,Malacria
, p. 138 - 140 (2001)
Rearrangement of silylated vinyloxiranes into highly functionalized α-silylated-β,γ-unsaturated aldehydes occurs with total chirality transfer and retention of double bond configuration under Pd(0) catalysis. We show that this reaction is a versatile tool in the field of total stereoselective synthesis: enantiomerically pure lactones are obtained. The pheromone 6-n-undecyltetrahydro-2-pyrone 2 and massoilactone, 5-hydroxy-2-decenoic acid lactone 3, are synthesized. We describe herein a novel highly diastereoselective route to α,β-unsaturated-γ-silylated-δ-substituted-δ-lact ones 1.
General, Highly Selective Synthesis of 1,3- and 1,4-Difunctionalized Building Blocks by Regiodivergent Epoxide Opening
Funken, Nico,Mühlhaus, Felix,Gans?uer, Andreas
, p. 12030 - 12034 (2016)
We describe a regiodivergent epoxide opening (REO) featuring a catalyst-controlled synthesis of enantiomerically and diastereomerically highly enriched or pure syn- and anti- 1,3- and 1,4-difunctionalized building blocks from a common epoxide precursor. The REO is attractive for natural product synthesis and as a branching reaction for diversity-oriented synthesis with epoxides.
Enzyme catalysed lactonization of 3,5 dihydroxy esters: Enantioselective synthesis of naturally occurring 3-hydroxy-5-decanolide, (-)-massoialactone, and 3-hydroxy-5-icosanolide
Bonini,Pucci,Racioppi,Viggiani
, p. 29 - 32 (1992)
Synthesis of optically active (+)-3-hydroxy-5-decanolide, (-)-massoialactone and of the recently isolated 3-hydroxy-5-icosanolide was achieved by enzyme-catalysed lactonization of racemic 3,5 dihydroxy esters with PPL in dry Et2O. Ees vary from 86% up to >98%.
Preparation method of (R)-(-)-massoialactone
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Paragraph 0057; 0059-0062, (2019/12/25)
The invention discloses a preparation method of (R)-(-)-massoialactone. The preparation method includes the following steps: in a solvent, under the action of a copper salt, an alkali and a ligand, beta,gamma-unsaturated ester and n-hexanal are subjected to a reaction shown in the specification to obtain (R)-(-)-massoalactrone; the copper salt is Cu(CH3CN)4PF6 or the alkali is Barton's Base, alkali metal tert-butanol salt or the ligand is (R,R)-Ph-BPE or (S)-DTBM-SEGPHOS. (R)-(-)-massoialactone can be obtained by one-step reaction with high yield and ee value; compared with other methods in the prior art, the method has many advantages, such as simple route, easy access to raw materials, mild conditions and the like, and has obvious advantages.
Enzyme-mediated enantioselective hydrolysis of 1,2-diol monotosylate derivatives bearing an unsaturated substituent
Matsumoto,Oohana,Hashimoto,Usuda,Shimoda,Ohshima,Suzuki,Togawa
, p. 3981 - 3988 (2018/06/15)
We have succeeded in the easy preparation of optically active 1,2-diol monotosylates bearing an unsaturated substituent via enzymatic hydrolysis. Lipase PS quickly catalyzes the hydrolyses of 2-acetoxybut-3-enyl tosylate, which has a double bond, and 2-acetoxybut-3-ynyl tosylate, which has a triple bond, with excellent enantioselectivity to afford the corresponding optically active compounds. The reaction is also applicable to acetates with a longer chain, which has a double bond at the terminus. To demonstrate the applicability of this method, enantiomerically pure (R)-massoialactone, a natural coconut flavor, has been synthesized from racemic 2-acetoxypent-4-enyl tosylate in several steps. Furthermore, the enzyme can recognize the stereochemistry of olefins, and the (Z)-alkenyl structure is more suitable for the enantioselective hydrolysis than the (E)-isomer.
Rationally Designed Chiral Synthons Enabling Asymmetric Z- and E-Selective Vinylogous Aldol Reactions of Aldehydes
Padarti, Akhil,Han, Hyunsoo
supporting information, p. 1448 - 1452 (2018/03/09)
In a conceptually different approach, highly stereoselective 2-oxonia-Cope rearrangement reactions between rationally designed nonracemic vinylogous aldolation synthons and aldehydes are described to provide δ-hydroxy-α,β-unsaturated esters with excellent
Asymmetric Synthesis of α,β-Unsaturated δ-Lactones through Copper(I)-Catalyzed Direct Vinylogous Aldol Reaction
Zhang, Hai-Jun,Yin, Liang
supporting information, p. 12270 - 12279 (2018/09/25)
A simple methodology for the asymmetric synthesis of chiral α,β-unsaturated δ-lactones was achieved by copper(I)-catalyzed direct vinylogous aldol reaction (DVAR) of β,γ-unsaturated esters and various aldehydes, including aromatic aldehydes, heteroaromatic aldehydes, α,β-unsaturated aldehydes, and aliphatic aldehydes. For aromatic and heteroaromatic aldehydes, a one-pot reaction consisting of DVAR, isomerization of the unsaturated carbon-carbon double bond from (E)-form to (Z)-form, and subsequent intramolecular transesterification was required to get the lactones in moderate to high yields with high enantioselectivity. For α,β-unsaturated and aliphatic aldehydes, the DVAR proceeded directly to afford the lactones in moderate yields with high enantioselectivity. In the DVAR, various functional groups were well tolerated. Moreover, the methodology was nicely applicable to the aldehyde group distributed in natural products, derivatives of natural product, and derivatives of drug molecules (atomoxetine and naproxen). The mechanism studies revealed that α-addition was reversible and not favored, which accounted for the excellent regioselectivity in the DVAR. The copper(I)-dienolate species generated through deprotonation was proposed to form an equilibrium with an allylcopper(I) species, which reacted with aldehydes to afford the DVAR products through a catalytic asymmetric allylation of aldehydes. Finally, the robustness of the present reaction was demonstrated by a gram-scale reaction, and the utility of the present methodology was showcased by the formal asymmetric synthesis of ezetimibe and fostriecin.
