- Total syntheses of Prelactone V and Prelactone B
-
The total syntheses of natural products Prelactone-V and Prelactone-B have been accomplished by a novel Chiron approach starting from D-glucose. The synthesis involves isopropylidene acetal formation of D-glucose using Poly(4-vinylpyridine) supported iodine as a catalyst, Tebbe olefination, Grignard reaction, Wittig olefination, selective mono deprotection of acetal using PMA/SiO2, hydrogenation and anti-1,3-diol formation are as key steps.
- Raghavendra,Tadiparthi, Krishnaji,Yadav
-
-
- Anti-Aldol reactions of chiral alcohol-substituted vinylogous urethanes and the synthesis of (-)-prelactone B
-
This paper describes a convenient and efficient method for synthesizing chiral alcohol-substituted vinylogous urethanes, in which the double bond has E configuration was determined by single crystal X-ray analysis. In addition, we investigated the anti-aldol reactions of these chiral vinylogous urethane anions. The use of (1S,2R,4R)-1-(hydroxydiphenylmethyl)-7,7-dimethylbicyclo[2,2, 1]-heptan-2-ol as a chiral auxiliary, provided the best enantioselectivities, and the resulting vinylogous urethane lactone could be used for the synthesis of (-)-prelactone B. A plausible mechanism for the generation of major enantiomeric isomer was discussed.
- Li, Yu-Jang,Hung, Hsiu-Yin,Liu, Yu-Wei,Lin, Pei-Jhen,Huang, Hung-Jyun
-
p. 927 - 935
(2011/03/19)
-
- Asymmetric synthesis of chiral δ-lactones containing multiple contiguous stereocenters
-
A versatile methodology for the asymmetric synthesis of chiral δ-lactones containing multiple contiguous stereocenters has been developed that relies on a series of Evans' aldol, hydroxyl-directed cyclopropanation, methanolysis, and Hg(II) mediated cyclopropane ring-opening reactions for stereocontrol.
- Peed, Jennifer,Perinan Dominguez, Ignacio,Davies, Iwan R.,Cheeseman, Matt,Taylor, James E.,Kociok-Koehn, Gabriele,Bull, Steven D.
-
supporting information; experimental part
p. 3592 - 3595
(2011/09/21)
-
- Total asymmetric syntheses of β-hydroxy-δ-lactones via umpolung with sulfur dioxide
-
Cyclic stereotriads and stereotetrads of the β-hydroxy-d-lactone type, e.g. prelactonesBandE, commonin polyketides and polypropionates, are prepared via SO2-induced oxyallylations of enoxysilanes with (1E,3Z)-1-(1-phenylethoxy) penta-1,3-dien-3-yl carboxylates. Using (Z)- or (E)-enoxysilanes both 4,5-cis- or 4,5-trans-d-lactones are obtained. Depending on the reduction method applied to the obtained aldol intermediates 5,6-trans or 5,6-cis-derivatives are formed. The d-lactones can be prepared in both their enantiomeric forms depending on the (1R)- or (1S)-configuration of the starting 1-(1-phenylethoxy)penta-1,3- dienes.
- Exner, Claudia J.,Laclef, Sylvain,Poli, Florent,Turks, Maris,Vogel, Pierre
-
supporting information; experimental part
p. 840 - 845
(2011/04/16)
-
- Application of silacyclic allylsilanes to the synthesis of β-hydroxy-δ-lactones: synthesis of Prelactone B
-
Silacyclic allylsilanes generated through a silene-diene Diels-Alder cycloaddition represent versatile bifunctional reagents for organic synthesis. This is demonstrated in a short stereocontrolled synthesis of (±)-Prelactone B.
- Sellars, Jonathan D.,Steel, Patrick G.
-
experimental part
p. 5588 - 5595
(2009/12/24)
-
- First concise total synthesis of 5-epi-prelactone B
-
First short total synthesis of 5-epi-prelactone B has been achieved involving Sharpless asymmetric epoxidation and intramolecular hydride transfer reaction for formation of the aldol product by nonaldol chemistry as the key steps. Copyright Taylor & Francis Group, LLC.
- Srihari,Ravindar,Somaiah,Yadav
-
p. 1389 - 1397
(2008/09/20)
-
- Silenes in organic synthesis: A short synthesis of prelactone B
-
The development of a synthetic methodology for the generation of silacyclohexenes through the cycloaddition of silenes with dienes and their subsequent elaboration to δ-lactones was discussed. It was found that the allyl silane component of the silacycloh
- Sellars, Jonathan D.,Steel, Patrick G.
-
p. 3223 - 3224
(2008/03/14)
-
- A convergent route to β-hydroxy δ-lactones through Prins cyclisation as the key step: Synthesis of (+)-prelactones B, C and V
-
Reactions of homoallylic alcohols with aldehydes in the presence of acid catalysts gave multisubstituted tetrahydropyrans with the creation of one to three new stereogenic centres in a single-pot process. The utility of this approach is extended to the en
- Yadav,Reddy, M. Sridhar,Prasad
-
p. 2133 - 2136
(2007/10/03)
-
- An asymmetric synthesis of (-)-prelactone B
-
An efficient synthesis of (-)-prelactone B has been developed using 1,2-cyclohexylidene glyceraldehyde as the chiral template. The key features of the synthesis were stereoselective crotylation of 1,2-cyclohexylidene glyceraldehyde and enantioselective re
- Salaskar, Avinash A.,Mayekar, Narayan V.,Sharma, Anubha,Nayak, Sandip K.,Chattopadhyaya, Angshuman,Chattopadhyay, Subrata
-
p. 2777 - 2781
(2007/10/03)
-
- Application of sulfur ylide mediated epoxidations in the asymmetric synthesis of β-hydroxy-δ-lactones. Synthesis of a mevinic acid analogue and (+)-prelactone B
-
Catalytic and stoichiometric asymmetric sulfur ylide reactions were employed to prepare alkyl-aryl epoxide intermediates in a convergent manner. These epoxides were utilized in efficient syntheses of the mevinic acid analogue 1 and prelactone B. Graphical abstract.
- Aggarwal, Varinder K.,Bae, Imhyuck,Lee, Hee-Yoon
-
p. 9725 - 9733
(2007/10/03)
-
- An efficient synthesis of (+)-prelactone B
-
An enantioselective synthesis of (+)-prelactone B 1 has been achieved on a multigram scale starting from a known bicyclic precursor 2. The key feature of the strategy is the generation of 3-stereogenic centres from a single bicyclic precursor, which has b
- Yadav,Reddy, K. Bhaskar,Sabitha
-
p. 6475 - 6476
(2007/10/03)
-
- A short and efficient synthesis of (+)-prelactone B
-
The asymmetric total synthesis of (+)-prelactone B, a biologically important natural β-hydroxy-δ-lactone derivative that contains a 2,3-trans-dialkylpyran ring system, is described. This approach involves the use of a very efficient oxazolidinone-mediated anti-aldol reaction, and a diastereoselective coupling between a ketene silyl acetal with an aldehyde followed by lactonization.
- Dias, Luiz C.,Steil, Leonardo J.,Vasconcelos, Valeria De A.
-
p. 147 - 150
(2007/10/03)
-
- Synthesis of (+)-prelactone B
-
Radical-mediated opening of a trisubstituted epoxy alcohol using cp2TiCl was followed by diastereoselective reduction of the resulting product with a centrally located methylene group, flanked on both sides by two chiral hydroxyl-bearing carbon
- Chakraborty, Tushar K.,Tapadar, Subhasish
-
p. 2541 - 2543
(2007/10/03)
-
- Asymmetric Synthesis of 4,5-Disubstituted 3-Hydroxy δ-Lactones: Prelactone B and Prelactone V
-
An efficient asymmetric synthesis of δ-lactones such as prelactone B has been developed. As key steps, the SAMP/RAMP-hydrazone methodology for the synthesis of 2-methylenated 1,3-diols and a homogenous hydrogenation were used.
- Enders, Dieter,Haas, Mareile
-
p. 2182 - 2184
(2007/10/03)
-
- The β-lactone route to β-hydroxy or α,β-unsaturated γ- and δ-lactones. Syntheses of (±)-Massoialactone and (±)-Prelactone B
-
Aqueous HF promotes the translactonization of silyloxy β-lactones into β-hydroxy or α,β-unsaturated γ- and δ-lactones. The reaction is studied from a theoretical point of view and applied to the racemic synthesis of two natural bioactive δ-lactones.
- Fournier, Lycia,Gaudel-Siri, Anouk,Kocieński, Philip J.,Pons, Jean-Marc
-
p. 107 - 111
(2007/10/03)
-
- Enantioselective Synthesis of γ,δ-Disubstituted β-Hydroxy δ-Lactones from Furans: Synthesis of (+)-Prelactone B and its C-4 Epimer
-
A new method for the enantioselective synthesis of γ,δ- disubstituted β-hydroxy δ-lactones (5,6-dialkyl-5,6-dihydropyran-2- ones) is reported and exemplified for (+)-prelactone B and its C-4 epimer. Our approach is based on the ring-enlargement of suitably functionalized optically pure 4-hydroxycyclopentanones, which are readily obtained from chiral 4-hydroxycyclopent-2-enones derived from furans. The procedure is amenable to the large-scale synthesis of the title compounds.
- Csák?, Aurelio G.,Mba, Myriam,Plumet, Joaquín
-
p. 2092 - 2094
(2007/10/03)
-
- Enantioselective synthesis of prelactone B using a proline-catalyzed crossed-aldol reaction
-
Catalytic enantioselective synthesis of prelactone B has been achieved in only four steps. A direct proline-catalyzed aldehyde-aldehyde aldol reaction is employed as the sole source of chirality.
- Pihko, Petri M.,Erkkil?, Anniina
-
p. 7607 - 7609
(2007/10/03)
-
- Synthesis of prelactone B
-
Prelactone B (1a) and its isomer 1b are possible products of a truncated avermectin polyketide synthase. In order to make them available as reference compounds they were synthesized in a six-step synthesis with 56% overall yield.
- Hanefeld,Hooper,Staunton
-
p. 401 - 403
(2007/10/03)
-