84519-53-9Relevant academic research and scientific papers
Versicolactones A and B: Total synthesis and structure revision
Wang, Liping,Zhu, Weiming
supporting information, p. 6729 - 6731 (2013/11/19)
To further determine absolute configurations of versicolactones A and B, total synthesis of versicolactones A and B and their six stereoisomers were reported in this Letter. The 1H and 13C NMR spectra of the synthetic erythro-stereoisomers matched perfectly with those of the natural products. Combined with the comparison of the specific rotations, the absolute configuration of versicolactones A and B were revised as (4Z,6R,7S)- and (4E,6R,7S)- from the corresponding (4Z,6R,7R)- and (4E,6R,7R)-6,7-dihydroxyocta- 2,4-dien-4-lactone, respectively.
On the origins of diastereoselectivity in the conjugate additions of the antipodes of lithium N-benzyl-(N-α-methylbenzyl)amide to enantiopure cis- and trans-dioxolane containing α,β-unsaturated esters
Davies, Stephen G.,Foster, Emma M.,Frost, Aileen B.,Lee, James A.,Roberts, Paul M.,Thomson, James E.
supporting information; experimental part, p. 6186 - 6200 (2012/09/05)
"Matching" and "mismatching" effects in the doubly diastereoselective conjugate additions of the antipodes of lithium N-benzyl-(N-α-methylbenzyl)amide to enantiopure cis- and trans-dioxolane containing α,β-unsaturated esters have been investigated. High levels of substrate control were established first upon conjugate addition of achiral lithium N-benzyl-N-isopropylamide to both tert-butyl (S,S,E)-4,5-O- isopropylidene-4,5-dihydroxyhex-2-enoate and tert-butyl (4R,5S,E)-4,5-O- isopropylidene-4,5-dihydroxyhex-2-enoate. However, upon conjugate addition of lithium (R)-N-benzyl-(N-α-methylbenzyl)amide and lithium (S)-N-benzyl-(N-α-methylbenzyl)amide to these substrates, neither reaction pairing reinforced the apparent sense of substrate control. These reactions do not, therefore, conform to the classical doubly diastereoselective "matching" or "mismatching" pattern usually exhibited by this class of reaction. A comparison of these reactions with the previously reported doubly diastereoselective conjugate addition reactions of lithium amide reagents to analogous substrates is also discussed.
Synthesis and bioluminescence-inducing properties of autoinducer (S)-4,5-dihydroxypentane-2,3-dione and its enantiomer
Kadirvel, Manikandan,Stimpson, William T.,Moumene-Afifi, Souad,Arsic, Biljana,Glynn, Nicola,Halliday, Nigel,Williams, Paul,Gilbert, Peter,McBain, Andrew J.,Freeman, Sally,Gardiner, John M.
scheme or table, p. 2625 - 2628 (2010/07/13)
The autoinducer (4S)-4,5-dihydroxypentane-2,3-dione ((S)-DPD, AI-2) facilitates chemical communication, termed 'quorum sensing', amongst a wide range of bacteria, The synthesis of (S)-DPD is challenging in part due to its instability. Herein we report a novel synthesis of (S)-DPD via (2S)-2,3-O-isopropylidene glyceraldehyde, through Wittig, dihydroxylation and oxidation reactions, with a complimentary asymmetric synthesis to a key precursor. Its enantiomer (R)-DPD, was prepared from d-mannitol via (2R)-2,3-O-isopropylideneglyceraldehyde. The synthesized enantiomers of DPD have AI-2 bioluminescence-inducing properties in the Vibrio harveyi BB170 strain.
Total synthesis of (+)-varitriol
Palik, Miroslav,Karlubikova, OL'Ga,Lasikova, Angelika,Kozisek, Jozef,Gracza, Tibor
experimental part, p. 709 - 715 (2009/07/19)
The total synthesis of natural (+)-varitriol (1) was accomplished by starting from dimethyl L-tartrate. The key features were a substrate selective and diastereoselective PdII-catalysed bicyclisation of unsaturated protected triol 9 followed by regioselective ring-opening of bicyclic skeleton 10. The absolute configuration of the target was confirmed by single-crystal X-ray analysis for the first time.
Synthesis of β,γ-disubstituted-γ-lactones through a Johnson-Claisen rearrangement: a short route to xylobovide, nor-canadensolide, canadensolide, sporothriolide and santolinolide
Fernandes, Rodney A.,Ingle, Arun B.,Chavan, Vijay P.
experimental part, p. 2835 - 2844 (2010/04/02)
The Johnson-Claisen rearrangement of allyl alcohols with chiral vicinal diol functionality was employed to access chiral β,γ-disubstituted-γ-lactones in high enantio- and diastereoselectivity. These were efficiently converted into nor-canadensolide, the advanced γ-(lactone-lactol) intermediate for xylobovide, canadensolide and sporothriolide and the lactone moiety of the santolinolides.
Stereoselective synthesis of 1,2-13C2-L-fucose, 1,2-13C2-fucono-γ-lactone and 1,2- 13C2-fucono-γ-lactol from non-sugar starting material
Gardiner, John M.,Panchal, Nitesh R.,Stimpson, William T.,Herbert, John M.,Ellames, George J.
, p. 2685 - 2687 (2007/10/03)
An efficient synthesis is reported for the preparation of L-fucose, and of L-fucofuranose, from 1. The route is designed to facilitate 13C labelling at C1 and/or C2, and the synthesis of 1,2-13C 2-fucose as its tetraacetate is described. The C2 and C3 stereo-centres are introduced using asymmetric dihydroxylation, and the lactone ring size resulting from cyclisation of 4 was controlled to provide the L-fucofuranone 5, whose structure was unambiguously established by X-ray crystal analysis of the derived trisilyl ether 6. Generation of the fucose lactol 7 by reduction of 6 followed by deprotection then provided L-fucose, isolated as its peracetate 8. Georg Thieme Verlag Stuttgart.
The use of π-allyltricarbonyliron lactone complexes in the synthesis of the resorcylic macrolides α- and β-zearalenol
Burckhardt, Svenja,Ley, Steven V.
, p. 874 - 882 (2007/10/03)
A highly stereoselective synthesis of the natural products α- and β-zearalenol 1 and 2 has been achieved using π-allyltricarbonyliron lactone complexes to control the 1,5-stereochemical relationship of the oxygen functionalities found in these resorcylic macrolides.
On the selectivity of oxynitrilases towards α-oxygenated aldehydes
Bianchi, Paola,Roda, Gabriella,Riva, Sergio,Danieli, Bruno,Zabelinskaja-Mackova, Antonina,Griengl, Herfried
, p. 2213 - 2220 (2007/10/03)
Different α-alkoxy and α,β-di-alkoxy substituted aldehydes have been submitted to the catalytic action of the oxynitrilases from almond (PaHNL) or from Hevea brasiliensis (HbHNL), in order to explore the possibility of using these enzymes for the preparation of complex cyanohydrins. The selectivity of both enzymes towards these compounds was found to be largely dependent on the substitutents, being low with the aldehydes carrying the sterically more demanding phenyl substituent. Contrary to the chemical addition of HCN, which always occurs with a slight preference for the formation of the anti diastereoisomers, the enzymatic cyanuration - occurring with a facial preference, Si or Re according to the biocatalyst used - gave a mixture of cyanohydrins that, depending on the starting enantiomeric aldehyde, can be enriched in the syn diastereoisomers.
The use of π-allyltricarbonyliron lactone complexes in the synthesis of the resorcylic macrolides α- and β-zearalenol
Ley, Steven V.,Burckhardt, Svenja
, p. 3028 - 3030 (2007/10/03)
A highly stereoselective synthesis of α- and β-zearalenol 1 and 2 is accomplished utilising π-allyltricarbonyliron lactone complexes 5 and 6 to establish the 1,5-stereochemical relationship of oxygen functionalities present in the natural products. The Royal Society of Chemistry 2000.
Synthesis of amino sugars through a highly diastereoselective dipolar cycloaddition. Enantioselective synthesis of the carbohydrate segment of Sch 38516
Xu, Zhongmin,Johannes, Charles W.,La, Daniel S.,Hofilena, Gloria E.,Hoveyda, Amir H.
, p. 16377 - 16390 (2007/10/03)
A concise and stereoselective route for the synthesis of the carbohydrate moiety of the antifungal agent Sch 38516 is described. The synthesis scheme includes a dipolar cycloaddition, which is rendered diastereoselective through the use of a readily available and easily removable chiral auxiliary.
