- The synthesis of medium-chain-length β-hydroxy esters via the reformatsky reaction
-
The synthesis of medium-chain-length β-hydroxy esters in good yield via the Reformatsky reaction is described. This work will be used as the basis for further investigation of hydroxyalkanoate polymers as potential feedstock for biofuel production.
- Sailer, Miloslav,Dubicki, Krystyn I.,Sorensen, John L.
-
-
- Total synthesis and structural validation of cyclodepsipeptides solonamide A and B
-
Microorganisms are an attractive source of new natural products with antimicrobial properties, and the marine environment constitutes a prolific resource of bioactive microorganisms. During a global research expedition (Galathea III), two depsipeptides, solonamide A and solonamide B, were isolated from the marine bacterium Photobacterium halotolerance and were found to inhibit virulence gene expression in the serious human pathogen, Staphylococcus aureus. They act by interfering with the agr quorum sensing system and show resemblance to the endogenous S. aureus quorum sensing peptide, autoinducing peptide I (AIP-I). To enable more comprehensive studies, we embarked on the chemical synthesis of solonamides A and B. The key synthetic steps were formation of the (R)-β-hydroxy-fatty-acids by stereo-selective aldol reactions and a cyclative macrolactamization, which proceeded under highly dilute conditions. Thus, the first total syntheses of the solonamides corroborated the originally assigned structures, and by changing the stereochemistry of the auxiliary in the aldol steps we gained access to the natural products as well as their β3-epimers.
- Kitir, Betül,Baldry, Mara,Ingmer, Hanne,Olsen, Christian A.
-
p. 7721 - 7732
(2014/12/10)
-
- Synthesis and Suzuki-Miyaura cross-coupling of enantioenriched secondary potassium β-trifluoroboratoamides: Catalytic, asymmetric conjugate addition of bisboronic acid and tetrakis(dimethylamino)diboron to α,β- unsaturated carbonyl compounds
-
Enantioenriched potassium β-trifluoroboratoamides have been synthesized via an asymmetric, copper-catalyzed 1,4-addition of tetrahydroxydiboron (BBA) and tetrakis(dimethylamino)-diboron to α,β-Unsaturated amides. These dibora reagents provide access to the desired organotri-fluoroborates using effective and atom economical sources of boron. The copper-catalyzed β-boration is extended to α,β- Unsaturated ketones and esters. The desired potassium organotrifluoroborates are synthesized with yields up to 92% and enantiomeric ratios up to 98:2. The enantioenriched potassium btrifluoroboratoamides are successfully cross-coupled with an array of aryl and heteroaryl chlorides in high yield with complete stereochemical fidelity as the transmetalation proceeds through an SE2 mechanism via an open transition state.
- Molander, Gary A.,Wisniewski, Steven R.,Hosseini-Sarvaria, Mona
-
p. 3037 - 3057
(2014/03/21)
-
- Hydroxyester disaccharides from fruits of cape gooseberry (Physalis peruviana)
-
The 3-O-β-D-glucopyranosyl-(1→6)-β-D -glucopyranoside of ethyl 3-hydroxyoctanoate and the diastereomeric 3-O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranosides of (3R) and (3S)-butyl 3-hydroxybutanoate, respectively, were isolated by chromatographic methods
- Mayorga, Humberto,Duque, Carmenza,Knapp, Holger,Winterhalter, Peter
-
p. 439 - 445
(2007/10/03)
-
- Formal synthesis of (-)-syringolide 1 starting from D-xylose based on a biomimetic strategy
-
An expeditious and practical synthertic process for a nonproteinaceous elicitor, (-)-syringolide 1, has been developed in a short number of steps utilizing the putative biosynthetic pathway by featuring the elaboration of the protected D-xylose as a starting material.
- Yoda, Hidemi,Kawauchi, Miho,Takabe, Kunihiko,Hosoya, Ken
-
p. 1895 - 1898
(2007/10/03)
-
- SILICA SUPPORTED TETRABUTYLAMMONIUM FLUORIDE AS A CATALYST FOR THE SILYLATION OF CARBONYL ABD HYDROXY COMPOUNDS WITH ETHYLTRIMETHYLSILYLACETATE
-
the use of silica supported tetrabutylammonium fluoride (TBAF-SiO2) as a non hygroscopic catalyst for silylating ketones and aldehydes with ethyltrimethylsilylacetate (ETSA) gives predominantly kinetic and Z silylenolethers at room temperature.TBAF-SiO2/ETSA is also useful in the silylation of alcohols.
- Gambacorta, Augusto,Turchetta, Stefano,Botta, Maurizio
-
p. 2441 - 2448
(2007/10/02)
-