775343-12-9Relevant academic research and scientific papers
High-Pressure-Promoted and Facially Selective Diels-Alder Reactions of Enzymatically Derived cis-1,2-Dihydrocatechols and Their Acetonide Derivatives: Enantiodivergent Routes to Homochiral and Polyfunctionalized Bicyclo[2.2.2]octenes
Stewart, Scott G.,Harfoot, Gwion J.,McRae, Kenneth J.,Teng, Yinglai,Yu, Li-Juan,Chen, Bo,Cammi, Roberto,Coote, Michelle L.,Banwell, Martin G.,Willis, Anthony C.
, p. 13080 - 13095 (2020)
cis-1,2-Dihydrocatechols 5 (X = Me and Cl), which are available in the homochiral form through the whole-cell biotransformation of toluene and chlorobenzene, respectively, undergo Diels-Alder cycloaddition reactions with a range of electron-deficient dienophiles at 19 kbar (1.9 GPa). The favored products of such reactions are adducts of the general form 7 and that arise through the operation of a contrasteric or syn-addition pathway. In contrast, the acetonide derivatives of metabolites 5 undergo anti-selective addition reactions under the same conditions and so producing adducts of the general form 11. Bicyclo[2.2.2]octenes 7 and 11, which embody carbocyclic frameworks of opposite enantiomeric form, are useful scaffolds for chemical synthesis. Computational studies reveal that syn-adduct formation is kinetically and normally thermodynamically favored over anti-adduct formation when the free diols 5 are involved, but the reverse is so when the corresponding acetonides participate as the 4?-addend. Furthermore, the reactions become more exothermic as pressure increases while, concurrently, the activation barrier diminishes and at 6 GPa (60 kbar) almost vanishes.
A chemoenzymatic synthesis of the cis-decalin core associated with the novel anti-mitotic agent phomopsidin: Some observations concerning a high-pressure-promoted diels-alder cycloaddition reaction of (1S,2R)-3-methyl-cis-1,2-dihydrocatechol and the anionic oxy-cope rearrangement of compounds derived from the adduct
Banwell, Martin G.,Edwards, Alison J.,McLeod, Malcolm D.,Stewart, Scott G.
, p. 641 - 644 (2007/10/03)
The enantiomerically pure and enzymatically derived cis-1,2-dihydrocatechol 2 engages in a diastereofacially selective Diels-Alder cycloaddition reaction with commercially available lactone 3 at 19 kbar to afford adduct 4, which is readily elaborated to the diene-ol 13. Treatment of this last compound with KH/18 [crown]-6 resulted in successive anionic oxy-Cope and 1,2-Wittig rearrangements to afford acyloin 14 embodying the cis-decalin core associated with the natural product phomopsidin (1). Compound 16 also engages in an anionic oxy-Cope rearrangement reaction to give, depending on the molar equivalents of base used, either the cis-decalin 17 or the hexahydroindene 18. The structure of compound 18 has been established by single-crystal X-ray diffraction analysis.
