476452-95-6Relevant academic research and scientific papers
Concise Synthesis of Optically Pure syn-1,3-Diols by Stereoselective Desymmetrization of a Divinylcarbinol
Berkenbusch, Thilo,Brückner, Reinhard
, p. 1813 - 1816 (2003)
Divinylcarbinols 17 and 18, CS-symmetrical and cis-configured, were desymmetrized by Sharpless' asymmetric epoxidation. This furnished anti-configured monoepoxy alcohols 19 (85% ee) and 20 (94% ee), respectively, or their mirror images (ent-19, 84% ee; en
Synthesis of a Cn-Cn+6 building block common to important polyol,polyene antibiotics from a divinylcarbinol by a desymmetrizing sharpless epoxidation
Nachbauer, Luc,Brueckner, Reinhard
, p. 6545 - 6562 (2013/11/06)
A stereocontrolled synthesis of the enantiomerically pure epoxide 7b from propargyl ether 15 has been realized in 15 steps. Epoxide 7b represents a building block for the "eastern" moieties of the title compounds. Key steps in our approach were a desymmetrizing Sharpless epoxidation (→a€‰anti,cis-16), the selective processing of the bis-enolate of the bis(tert-butyl alkoxyacetate) 11 through a diastereoselective [2,3]-Wittig rearrangement (→a€‰syn,syn-9), and a stereo- and chemoselective iodolactonization (→a€‰35). The CO2H groups of dicarboxylic acid 37 were differentiated in a one-pot bis-oxidation reaction. The latter entailed the novel transformation of HO2CCH2-O-alkyl into AcOCH2-O-alkyl. The termini of a bis(tert-butyl alkoxyacetate) have been differentiated by forming the bis-enolate and engaging one enolate in a diastereoselective [2,3]-Wittig rearrangement. A diastereo- and chemoselective iodolactonization established the stereocenter of the epoxide ring. Copyright
Stereocomplementary desymmetrizations of divinylcarbinols by zirconium(IV)- vs. titanium(IV)-mediated asymmetric epoxidations
Kramer, Rainer,Berkenbusch, Thilo,Brueckner, Reinhard
supporting information; experimental part, p. 1131 - 1148 (2009/06/17)
Substituted Cs-symmetric penta-1,4-dien-3-ols ("divinylcarbinols") containing cis- or trans-disubstituted C=C bonds were desymmetrized by asymmetric monoepoxidations. Sharpless conditions gave anti-configured monoepoxides. For cis,cis-divinylca
Total synthesis of (+)-amphidinolide A. Assembly of the fragments
Trost, Barry M.,Wrobleski, Stephen T.,Chisholm, John D.,Harrington, Paul E.,Jung, Michael
, p. 13589 - 13597 (2007/10/03)
The structure elucidation of (+)-amphidinolide A, a cytotoxic macrolide, has been accomplished by employing a combination of total synthesis and NMR spectroscopic analysis. Amphidinolide A possesses two skipped 1,4-diene subunits which are accessible by ruthenium-catalyzed alkene-alkyne couplings. Previous total syntheses had revealed that the reported structure was incorrect; therefore, to incorporate maximum flexibility into the synthesis, with the ultimate goal of determining the correct structure, a highly convergent approach was chosen. Furthermore, liberal use was made of catalytic asymmetric transformations to set individual stereocenters. Three different strategies were envisioned for the end game, and due to the highly convergent nature of the synthesis, all three routes disconnect to the same three key intermediates, 5, 6, and 7. Diastereomers of 6 and 7 were easily prepared by modification of the synthetic routes to allow access to multiple diastereomers of 1 for structural determination.
Ruthenium-catalyzed alkene-alkyne coupling: Synthesis of the proposed structure of amphidinolide A
Trost, Barry M.,Chisholm, John D.,Wrobleski, Stephen T.,Jung, Michael
, p. 12420 - 12421 (2007/10/03)
The ruthenium-catalyzed alkene-alkyne coupling provides a powerful method for the synthesis of 1,4 dienes and a way to simplify synthetic strategy. The latter potential is explored in the context of a synthesis of the assigned structure of amphidinolide A
