91796-52-0Relevant academic research and scientific papers
A Unified Synthetic Approach to Optically Pure Curvularin-Type Metabolites
Allu, Srinivasa Rao,Banne, Sreenivas,Jiang, Jia,Qi, Na,Guo, Jian,He, Yun
, p. 7227 - 7237 (2019/06/07)
A unified and concise approach to the synthesis of nine curvularin-type metabolites and two analogues has been developed with few steps and high yields. Among them, sumalactones A-D were synthesized for the first time. The key steps in this approach inclu
Total Synthesis of Tetraketide and Cryptorigidifoliol i via a Sequential Allylation Strategy
Padhi, Birakishore,Reddy, G. Sudhakar,Mohapatra, Debendra K.
, p. 2788 - 2796 (2016/12/06)
A unified and efficient synthetic route for both tetraketide (1) and cryptorigidifoliol I (2) has been devised successfully from commercially available starting materials in 11 and 17 steps, with 16% and 11% overall yields, respectively. Highlights of the syntheses involved sequential Lewis acid-catalyzed highly regio- and diastereoselective allylations and intramolecular Mitsunobu lactonization.
Addition of allylindium reagents to aldehydes substituted at Cα or Cβ with heteroatomic functional groups. Analysis of the modulation in diastereoselectivity attainable in aqueous, organic, and mixed solvent systems
Paquette, Leo A.,Mitzel, Thomas M.
, p. 1931 - 1937 (2007/10/03)
The stereochemical course of indium-promoted allylations to α- and β-oxy aldehydes has been investigated in solvents ranging from anhydrous THF to pure H2O. The free hydroxyl derivatives react with excellent diastereofacial control to give significantly heightened levels of syn-1,2-diols and anti-1,3-diols. Relative reactivities were determined in the α-series, and the hydroxy aldehyde proved to be the most reactive substrate. This reactivity ordering suggests that the selectivity stems from chelated intermediates. The rate acceleration observed in water can be heightened by initial acidification. Indeed, the indium-promoted allylation reaction mixtures become increasingly acidic on their own. Preliminary attention has been accorded to salt effects, and tetraethylammonium bromide was found to exhibit a positive synergistic effect on product distribution. Finally, mechanistic considerations are presented in order to allow for assessment of the status of these unprecedented developments at this stage of advancement of the field.
Total Synthesis of (-)-Colletol
Keck, Gary E.,Murry, Jerry A.
, p. 6606 - 6611 (2007/10/02)
The first total synthesis of the unsymmetrical bis-macrolide (-)-colletol is described.The synthesis involves a Lewis acid mediated addition of triphenylallylstannane to aldehyde 14 to set the C12 stereochemistry.The penultimate step utilized m
5. Synthesis and Reactions of Optically Active 1,3-Diols
Roesslein, Lukas,Tamm, Christoph
, p. 47 - 56 (2007/10/02)
The 'syn'-1,3-diols 3, 4, and 5 with C7, C6, and C5 chain, respectively, were synthesized from methyl hydrogen 3-hydroxyglutarate (2; Schemes 1 and 2).The latter is available in (R)- and (S)-configuration.Octyl (3R)-4-chloro-3-hydroxybutanoate (17) is an
Dramatic Effects of Oxygen Substituents on 1,3-Asymmetric Induction in Additions of Allyltriphenylstannane to β-Alkoxy Aldehydes: a Chemical and Spectroscopic Investigation
Keck, Gary E.,Castellino, Stephen,Wiley, Michael R.
, p. 5478 - 5480 (2007/10/02)
The level of stereoselectivity realized in the Lewis acid mediated additions of allyltriphenylstannane to β-alkoxy aldehydes chiral by virtue of substitution at C3 depends critically upon the choice of the β-oxygen substituent as well as the choice of Lewis acid.The chemical behavior seen in such addition reactions correlates very well with the solution structures of the Lewis acid complexes formed from such aldehydes and various Lewis acids, as determined by variable-temperature 1H and 13C NMR spectroscopy.
Acyclic Stereoselection. 22. Diastereofacial Selectivity in the Lewis Acid Mediated Reactions of Allylsilanes with Chiral Aldehydes and Enones
Heathcock, Clayton H.,Kiyooka, Syun-ichi,Blumenkopf, Todd A.
, p. 4214 - 4223 (2007/10/02)
The Lewis acid mediated reactions of chiral aldehydes 1-4 and enones 5-8 with allylsilanes 9 and 10 have been investigated.With aldehyde 1 and enones 5-7, modest diastereofacial preferences are seen, in the sense predicted by application of Felkin's model for asymmetric induction.Aldehydes 2-4 and enone 8 appear to react by way of chelated intermediates.With these four compounds, the diastereofacial preferences are rather large and are in the sense that is consistend with attack of the allylsilane on the least hindered face of the chelated intermediate.In the reaction of the trans and cis enones 6 and 8 with allyltrimethylsilane, a dramatic reversal of diastereofacial preference is observed; enone 6 gives a 84:14 ratio of products, while enone 8 provides a 10:90 mixture of the same products.
CONCERNING THE ROLE OF LEWIS ACIDS IN CHELATION CONTROLLED ADDITION TO CHIRAL ALKOXY ALDEHYDES
Reetz, M. T.,Kesseler, K.,Jung, A.
, p. 729 - 732 (2007/10/02)
Chiral α- and β-alkoxy aldehydes react stereoselectively with various C-nucleophiles in th epresence of Lewis acids to provide chelation controlled adducts.
