Journal of Advances in Education Research

Download PDF (299.1 KB) PP. 1 - 8 Pub. Date: January 1, 2021

DOI: 10.22606/jaer.2021.61001

• Syed R. Hussaini^*
  Department of Chemistry and Biochemistry, The University of Tulsa, 800 S. Tucker Dr., Tulsa, Oklahoma 74104, United States
• Jim Secka
  Department of Chemistry and Biochemistry, The University of Tulsa, 800 S. Tucker Dr., Tulsa, Oklahoma 74104, United States

Pentane and boat conformations help predict and understand the stereochemical outcome of several chemical reactions. This report presents two methods that teach the processes of drawing the lowest energy boat conformations and pentane conformations. Both techniques use cyclohexane drawings that students learn in undergraduate organic chemistry courses. We provide step-by-step instructions for both techniques and show that implementing these methods results in improved student performance in questions related to boat and pentane conformations.

upper-division undergraduate, graduate education, boat conformation, pentane conformations, syn-pentane interactions.

[1] 1. S. R. Hussaini (2014), “Converting chair-like transition states into zig-zag projections,” Resonance – Journal of Science Education, vol. 19, no. 9, pp. 846–850.

[2] 2. J. M. Hornback (2006), “Stereochemistry I: cis-trans isomers and conformers,” in Organic Chemistry 2 ed. Thomson Brooks/Cole, pp. 178–218.

[3] 3. J. Karty (2018), “Isomerism 1: conformers and constitutional isomers,” in Organic Chemistry 2 ed. Norton, pp. 165–207.

[4] 4. D. J. Nelson and C. N. Brammer (2011), “Toward consistent terminology for cyclohexane conformers in Introductory Organic Chemistry,” Journal of Chemical Education, vol. 88, no. 3, pp. 292–294.

[5] 5. K. A. Niederer, M. D. Fodor and A. J. Catino (2018), “A simple method for the visualization of chair and twistboat transition states in torsionally controlled addition reactions,” Journal of Chemical Education, vol. 95, no. 7, pp. 1230–1234.

[6] 6. W. von E. Doering and W. R. Roth (1962), “The overlap of two allyl radicals or a four-centered transition state in the Cope rearrangement,” Journal of Chemical Education, vol. 95, no.

[7] 7, pp. 1230–1234. 7. E. V. Anslyn and D. A. Dougherty (2004), “Thermal pericyclic reactions,” in Modern Physical Organic Chemistry. University Science Books, pp. 877–934.

[8] 8. E. L. Eliel, S. H. Wilen and L. N. Mander (1994), “Stereoselective synthesis,” in Stereochemistry of Organic Compounds. Wiley-Interscience, pp. 835–990.

[9] 9. P. S. Kalsi (2015), “Pericyclic Reactions,” in Stereochemistry: conformation and mechanism. New Age International Publishers, pp. 531–608.

[10] 10. A. M. M. Castro (2004), “Claisen rearrangement over the past nine years,” Chemical Reviews, vol. 104, no. 6, pp. 2939–3002.

[11] 11. R. E. Gawley (1996), “Aldol and Michael additions of allyls, enolates, and enolate equivalents,” in Principles of asymmetric synthesis 2 ed. Elsevier, pp. 245–334.

[12] 12. Y. Li, M. N. Paddon-Row and K. N. Houk (1990), “Transition structures for the aldol reactions of anionic, lithium, and boron enolates,” The Journal of Organic Chemistry, vol. 55, no. 2, pp. 481–493.

[13] 13. A. Bernardi, A. M. Capeli, C. Gennari, J. M. Goodman and I. Paterson (1990), “Transition-state modeling of the aldol reaction of boron enolates: a force field approach,” The Journal of Organic Chemistry, vol. 55, no. 11, pp. 3576–3581.

[14] 14. R. B. Grossman (2002), “Pericyclic reactions,” in The Art of Writing Reasonable Organic Reaction Mechanisms 2 ed. Springer, pp. 148–223.

[15] 15. J. E. Baldwin and C. Ullenius (1974), “Thermal isomerization of 1,2-dialkenylcyclopropanes,” Journal of the American Chemical Society, vol. 96, no. 5, pp. 1542–1547.

[16] 16. J. Lee, H. Kim and J. K. Cha (1995), “Diastereoselective synthesis of cis-1,2-dialkenylcyclopropanols and subsequent oxy-Cope rearrangement,” Journal of the American Chemical Society, vol. 117, no. 39, pp. 9919– 9920.

[17] 17. E. V. Anslyn and D. A. Dougherty (2004), “Strain and stability,” in Modern Physical Organic Chemistry. University Science Books, pp. 65–144.

[18] 18. D. Nasipuri (1994), “Conformations of acyclic molecules,” in Stereochemistry of Organic Compounds: Principles and Applications 2nd ed. New Age International Publisher, pp. 203–239.

[19] 19. R. W. Hoffmann, M. Stahl, U. Schopfer and G. Frenking (1998), “Conformation design of hydrocarbon backbones: a modular approach,” Chemistry – A European Journal, vol. 4, no. 4, pp. 559–566.

[20] 20. K. Burgess (2009), “Acyclic conformations,” in Organic Chemistry By Inquisition: 1. General Reactions. Inquisition Press, pp. 1–8.

[21] 21. K. C. Nicolaou and S. A. Snyder (2003), “Swinholide A,” in Classics in Total Synthesis II: More Targets, Strategies, Methods. Wiley–VCH, pp. 31–74.

[22] 22. S. Hanessian, V. Mascitti and S. Giroux (2004), “Total synthesis of the cytotoxic cyclodepsipeptide (–)- doliculide: the “ester” effect in acyclic 1,3-induction of deoxypropionates,” Proceedings of the National Academy of Sciences of the United States, vol. 101, no. 33, pp. 11996–12001.

[23] 23. J. Liu, S. Gao and M. Chen (2019), “Enantioselective syntheses of (E)-?,?-disubstituted homoallylic alcohols via BF3·OEt2-catalyzed aldehyde allylboration and analysis of the origin of E-selectivity: A1,2 allylic strain vs. synpentane interaction,” Tetrahedron, vol. 75, no. 31, pp. 4110–4117.

[24] 24. P. Maurin, S.-H. Kim, S. Y. Cho and J. K. Cha (2003), “On the mechanism of the anionic oxy-Cope rearrangement of trans-1,2-dialkenylcyclobutanols,” Angewandte Chemie International Edition, vol. 42, no. 41, pp. 5044–5047.

[25] 25. P. Leriverend (1991), “A simple way to draw the chair and boat conformation of cyclohexane,” Journal of Chemical Education, vol. 68, no. 11, pp. 957.

[26] 26. E. L. Eliel, S. H. Wilen and L. N. Mander (1994), “Configuration and conformation of cyclic molecules,” in Stereochemistry of Organic Compounds. Wiley-Interscience, pp. 665–834.

[27] 27. M. Hiersmann (1999), “The Pd(II)-catalyzed and the thermal Claisen rearrangement of 2-alkoxycarbonylsubstituted allyl vinyl ethers,” Synlett, vol. 1999, no. 11, pp. 1823–1825.

[28] 28. P. Wyatt and S. Warren (2007), “Control of stereochemistry — Introduction,” in Organic Synthesis: Strategy and Control. Wiley, pp. 372–398.