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General transformation in xanthate transfer reactions

General transformation in xanthate transfer reactions. Why use xanthate transfer reactions?. Retrosynthetic analysis of 10-norparvulenone and O -methylasparvenone. Overview. Barton-McCombie deoxygenation reaction. Competition experiment: expected product.

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General transformation in xanthate transfer reactions

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  1. General transformation in xanthate transfer reactions

  2. Why use xanthate transfer reactions?

  3. Retrosynthetic analysis of 10-norparvulenone and O-methylasparvenone

  4. Overview

  5. Barton-McCombie deoxygenation reaction

  6. Competition experiment: expected product

  7. Competition experiment: actual products

  8. b-scission of C-S vs. C-O bond

  9. Barton-McCombie deoxygenation mechanism

  10. Xanthate transfer chain process

  11. Radical Stabilization: Frontier Molecular Orbital theory

  12. Overview

  13. Preparation of xanthates

  14. Preparation of tertiary xanthates

  15. Formation of quaternary centers

  16. Reductive cleavage of the C-S bond

  17. Reduction of C-S bond with phosphorus reagents

  18. Access to synthetic equivalents of propargyl radicals

  19. Radical-polar crossover reactions

  20. Intermolecular oxidative radical alkylation

  21. Radical alkylation of different heteroaromatic systems

  22. Origin of regioselectivity

  23. Alkylation of 3,4-dihydro-2H-pyran

  24. Attempted trapping of oxocarbenium ion

  25. Synthesis of functionalized boronates

  26. Construction of the a-tetralone subunit of 10-norparvulenone and O-methylasparvenone

  27. Construction of the a-tetralone subunit of 10-norparvulenone and O-methylasparvenone

  28. Stereocontrolled carboazidation in the total synthesis of Hyacinthacine A1 and epi-3-Hyacinthacine A1

  29. Mechanism of Carboazidation

  30. Reversible Addition Fragmentation chain Transfer process

  31. Overview

  32. Limitations

  33. Conclusions

  34. Acknowledgements

  35. Stereocontrolled Carboazidation

  36. Requirements for radical chain reactions

  37. Xanthates and related derivatives

  38. Competing mechanisms

  39. Potential for intermolecular addition to unactivated olefins

  40. Intramolecular variant yields polycyclic structures

  41. Synthesis of 2,3-trans disubstituted tetrahydrofurans

  42. Synthesis of 2-sulfolenes: precursors to 1,3-dienes

  43. Xanthate transfer chain process

  44. Construction of a-amino acid derivatives

  45. C-alkylation of small peptides

  46. C-allylation of small peptides

  47. Radical-polar crossover reactions

  48. Construction of a-tetralone by Bos et al

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